Business Overview

Biogen Idec is a global biotechnology company that discovers, develops, manufactures and markets therapies for the treatment of neurodegenerative diseases, hemophilia and autoimmune disorders. Patients worldwide benefit from our leading multiple sclerosis therapies, and the company generates $5 billion in annual revenues.

Consolidation

Our consolidated financial statements reflect our financial statements, those of our wholly-owned subsidiaries and those of certain variable interest entities in which we are the primary beneficiary. For consolidated entities in which we own or are exposed to less than 100% of the economics, we record net income (loss) attributable to noncontrolling interests in our consolidated statements of income equal to the percentage of the economic or ownership interest retained in such entities by the respective noncontrolling parties. All material intercompany balances and transactions are eliminated in consolidation.

In determining whether we are the primary beneficiary of an entity, we apply a qualitative approach that determines whether we have both (1) the power to direct the economically significant activities of the entity and (2) the obligation to absorb losses of, or the right to receive benefits from, the entity that could potentially be significant to that entity. These considerations impact the way we account for our existing collaborative relationships and determine whether we consolidate companies or entities with which we have collaborative or other arrangements. Determination about whether an enterprise should consolidate a variable interest entity is required to be made continuously as changes to existing relationships or future transactions may result in us consolidating or deconsolidating our partner(s) to collaborations and other arrangements.

Use of Estimates

The preparation of our consolidated financial statements in accordance with U.S. GAAP requires management to make estimates, judgments, and assumptions that may affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. On an on-going basis, we evaluate our estimates and judgments and methodologies, including those related to revenue recognition and related allowances, our collaborative relationships, clinical trial expenses, the consolidation of variable interest entities, the valuation of contingent consideration resulting from a business combination, the valuation of acquired intangible assets including in-process research and development, inventory, impairment and amortization of long-lived assets including intangible assets, impairments of goodwill, share-based compensation, income taxes including the valuation allowance for deferred tax assets, the valuation of investments, derivatives and hedging activities, contingencies, litigation, and restructuring charges. We base our estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ from these estimates under different assumptions or conditions.

Revenue Recognition

We recognize revenue when all of the following criteria are met: persuasive evidence of an arrangement exists; delivery has occurred or services have been rendered; our price to the customer is fixed or determinable; and collectability is reasonably assured.

Product Revenues

Revenues from product sales are recognized when title and risk of loss have passed to the customer, which is typically upon delivery. However, sales of TYSABRI in the U.S. are recognized on the “sell-through” model, that is, upon shipment of the product by Elan Pharma International, Ltd. (Elan), an affiliate of Elan Corporation, plc, to its third party distributor rather than upon shipment to Elan. Product revenues are recorded net of applicable reserves for discounts and allowances.

Reserves for Discounts and Allowances

We establish reserves for trade term discounts, wholesaler incentives, Medicaid rebates, Veterans Administration (VA) and Public Health Service (PHS) discounts, managed care rebates, product returns and other governmental rebates or applicable allowances, including those associated with the implementation of pricing actions in certain of the international markets in which we operate. Reserves established for these discounts and allowances are classified as reductions of accounts receivable (if the amount is payable to our direct customer) or a liability (if the amount is payable to a party other than our customer). These reserves are based on estimates of the amounts earned or to be claimed on the related sales. Our estimates take into consideration our historical experience, current contractual and statutory requirements, specific known market events and trends, and forecasted customer buying patterns. Actual amounts may ultimately differ from our estimates. If actual results vary, we will need to adjust these estimates, which could have an effect on earnings in the period of adjustment. The estimates we make with respect to these allowances represent the most significant judgments with regard to revenue recognition.

Product revenue reserves are categorized as follows: discounts, contractual adjustments and returns.

Discount reserves include trade term discounts and wholesaler incentives. Trade term discounts and wholesaler incentive reserves primarily relate to estimated obligations for credits to be granted to wholesalers for remitting payment on their purchases within established incentive periods and credits to be granted to wholesalers for compliance with various contractually-defined inventory management practices, respectively. We determine these reserves based on our experience, including the timing of customer payments.

Contractual adjustment reserves primarily relate to Medicaid and managed care rebates, VA and PHS discounts and other governmental rebates or applicable allowances.

Product return reserves are established for returns expected to be made by wholesalers and are recorded in the period the related revenue is recognized, resulting in a reduction to product sales. In accordance with contractual terms, wholesalers are permitted to return product for reasons such as damaged or expired product. The majority of wholesaler returns are due to product expiration. Expired product return reserves are estimated through a comparison of historical return data to their related sales on a production lot basis. Historical rates of return are determined for each product and are adjusted for known or expected changes in the marketplace specific to each product.

In addition to the discounts and rebates described above and classified as a reduction of revenue, we also maintain certain customer service contracts with distributors and other customers in the distribution channel that provide us with inventory management and distribution services. We have established the fair value of these services and classified these customer service contracts as sales and marketing expense. If we had concluded that we did not receive a separate identifiable benefit or have sufficient evidence that the fair value did not exist for these services, we would have been required to classify these costs as a reduction of revenue.

In countries where we expect to collect receivables greater than one year, at the time of sale, we have discounted our revenues over the period of time that we estimate those amounts will be paid using our estimate of the country’s borrowing rate. The related receivables are classified at the time of sale as long-term assets. We will accrete interest income on these receivables, which will be recognized as a component of other income (expense), net within our consolidated statement of income.

We also distribute no-charge product to qualifying patients under our patient assistance and patient replacement goods program. This program is administered through one of our distribution partners, which ships product for qualifying patients from its own inventory received from us. Gross revenue and the related reserves are not recorded on product shipped under this program and cost of sales is recorded when the product is shipped.

Revenues from Unconsolidated Joint Business

We collaborate with Genentech on the development and commercialization of RITUXAN. Revenues from unconsolidated joint business consist of (1) our share of pre-tax co-promotion profits in the U.S.; (2) reimbursement of our selling and development expense in the U.S.; and (3) revenue on sales of RITUXAN in the rest of world, which consists of our share of pre-tax co-promotion profits in Canada and royalty revenue on sales of RITUXAN outside the U.S. and Canada by F. Hoffmann-La Roche Ltd. (Roche) and its sublicensees. Pre-tax co-promotion profits are calculated and paid to us by Genentech in the U.S. and by Roche in Canada. Pre-tax co-promotion profits consist of U.S. and Canadian sales of RITUXAN to third-party customers net of discounts and allowances less the cost to manufacture RITUXAN, third-party royalty expenses, and distribution, selling and marketing, and joint development expenses incurred by Genentech, Roche and us. We record our share of the pretax co-promotion profits in Canada and royalty revenues on sales of RITUXAN outside the U.S. on a cash basis. Additionally, our share of the pretax co-promotion profits in the U.S. includes estimates made by Genentech and those estimates are subject to change. Actual results may ultimately differ from our estimates.

Royalty Revenues

We receive royalty revenues on sales by our licensees of other products covered under patents that we own. We do not have future performance obligations under these license arrangements. We record these revenues based on estimates of the sales that occurred during the relevant period. The relevant period estimates of sales are based on interim data provided by licensees and analysis of historical royalties that have been paid to us, adjusted for any changes in facts and circumstances, as appropriate. We maintain regular communication with our licensees in order to assess the reasonableness of our estimates. Differences between actual royalty revenues and estimated royalty revenues are adjusted for in the period in which they become known, typically the following quarter. Historically, adjustments have not been material when compared to actual amounts paid by licensees. If we are unable to accurately estimate revenue, then we record revenues on a cash basis.

Milestone Revenues

We execute collaborative and other agreements which may contain milestone payments. Revenues from milestones, if they are considered substantive, are recognized upon successful accomplishment of the milestones. Determining whether a milestone is substantive involves judgment, including an assessment of our involvement in achieving the milestones and whether the amount of the payment is commensurate to our performance. If not considered substantive, milestones are initially deferred and recognized over the remaining performance obligation.

Multiple-Element Revenue Arrangements

We may, from time to time, enter into transactions that involve the sale of products and related services under multiple element arrangements. In accounting for these transactions, we allocate revenue to the various elements based on their fair value. The fair value of a revenue generating element can be based on current selling prices offered by us or another party for current products or management’s best estimate of a selling price for future products. Revenue allocated to an individual element is recognized when all other revenue recognition criteria are met for that element.

Fair Value Measurements

We have certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements.

Valuation of Investments

We validate the prices provided by our third party pricing services by reviewing their pricing methods and matrices, obtaining market values from other pricing sources, analyzing pricing data in certain instances and confirming that the relevant markets are active. After completing our validation procedures, we did not adjust or override any fair value measurements provided by our pricing services as of December 31, 2011 and 2010, respectively.

Our strategic investments in publicly traded equity securities are classified as Level 1 assets as their fair values are readily determinable and based on quoted market prices.

The majority of our financial assets and liabilities have been classified as Level 2. Our financial assets and liabilities (which include our cash equivalents, derivative contracts, marketable debt securities, and plan assets for deferred compensation) have been initially valued at the transaction price and subsequently valued, at the end of each reporting period, typically utilizing third party pricing services or other market observable data. The pricing services utilize industry standard valuation models, including both income and market based approaches and observable market inputs to determine value. These observable market inputs include reportable trades, benchmark yields, credit spreads, broker/dealer quotes, bids, offers, current spot rates and other industry and economic events.

We also maintain venture capital investments classified as Level 3 whose fair value is initially measured at transaction prices and subsequently valued using the pricing of recent financing or by reviewing the underlying economic fundamentals and liquidation value of the companies. These investments are the only investments for which we used Level 3 inputs to determine the fair value. These investments include investments in certain biotechnology oriented venture capital funds which primarily invest in small privately-owned, venture-backed biotechnology companies. The fair value of our investments in these venture capital funds has been estimated using the net asset value of the fund. The investments cannot be redeemed within the funds. Distributions from each fund will be received as the underlying investments of the fund are liquidated. The funds and therefore a majority of the underlying assets of the funds will not be liquidated in the near future. The underlying assets in these funds are initially measured at transaction prices and subsequently valued using the pricing of recent financings or by reviewing the underlying economic fundamentals and liquidation value of the companies that the funds invest in. We apply judgments and estimates when we validate the prices provided by third parties. While we believe the valuation methodologies are appropriate, the use of valuation methodologies is highly judgmental and changes in methodologies can have a material impact on our results of operations. Gains and losses (realized and unrealized) included in earnings for the period are reported in other income (expense), net.

Valuation of Contingent Consideration Resulting from a Business Combination

We record contingent consideration resulting from business combinations completed after January 1, 2009 at its fair value on the acquisition date. Each reporting period thereafter, we revalue these obligations and record increases or decreases in their fair value as an adjustment to contingent consideration expense within our consolidated statement of income. Changes in the fair value of the contingent consideration obligations can result from adjustments to the discount rates and periods, updates in the assumed achievement or timing of any development milestones or changes in the probability of certain clinical events and changes in the assumed probability associated with regulatory approval. These fair value measurements represent Level 3 measurements as they are based on significant inputs not observable in the market.

Significant judgment is employed in determining the appropriateness of these assumptions as of the acquisition date and for each subsequent period. Accordingly, changes in assumptions described above, could have a material impact on the amount of contingent consideration expense we record in any given period.

Other

The carrying amounts reflected in the consolidated balance sheets for cash equivalents, current accounts receivable, due from unconsolidated joint business, other current assets, accounts payable, and accrued expenses and other, approximate fair value due to their short-term maturities.

Cash and Cash Equivalents

We consider only those investments which are highly liquid, readily convertible to cash and that mature within three months from date of purchase to be cash equivalents. As of December 31, 2011 and 2010, cash equivalents were comprised of money market funds and commercial paper, repurchase agreements, and other debt securities with maturities less than 90 days.

Accounts Receivable

The majority of our accounts receivable arise from product sales and primarily represent amounts due from our wholesale distributors, public hospitals and other government entities. We monitor the financial performance and credit worthiness of our large customers so that we can properly assess and respond to changes in their credit profile. We provide reserves against trade receivables for estimated losses that may result from a customer’s inability to pay. Amounts determined to be uncollectible are charged or written-off against the reserve. To date, such losses have not exceeded management’s estimates.

Concentration of Credit Risk

Financial instruments that potentially subject us to concentrations of credit risk include cash and cash equivalents, investments, derivatives, and accounts receivable. We attempt to minimize the risks related to cash and cash equivalents and investments by using highly-rated financial institutions that invest in a broad and diverse range of financial instruments as previously defined by us. We have established guidelines relative to credit ratings and maturities intended to safeguard principal balances and maintain liquidity. Our investment portfolio is maintained in accordance with our investment policy, which defines allowable investments, specifies credit quality standards and limits the credit exposure of any single issuer. We minimize credit risk resulting from derivatives instruments by choosing only highly rated financial institutions as counterparties.

Concentrations of credit risk with respect to receivables, which are typically unsecured, are limited due to the wide variety of customers and markets using our products, as well as their dispersion across many different geographic areas. The majority of our accounts receivable arise from product sales in the United States and Europe and have standard payment terms which are generally between 30 and 90 days. We continue to monitor economic conditions, including the volatility associated with international economies, and associated impacts on the relevant financial markets and our business, especially in light of the global economic downturn. For additional information related to this concentration of credit risk, please read Note 5, Accounts Receivable to these consolidated financial statements.

As of December 31, 2011 and 2010, one wholesale distributor accounted for approximately 14.1% and 11.5% of consolidated receivables, respectively.

Inventory

Inventories are stated at the lower of cost or market with cost determined in a manner that approximates the first-in, first-out (FIFO) method. Included in inventory are raw materials used in the production of pre-clinical and clinical products, which are expensed as research and development costs when consumed.

Capitalization of Inventory Costs

We capitalize inventory costs associated with our products prior to regulatory approval, when, based on management’s judgment, future commercialization is considered probable and the future economic benefit is expected to be realized. We consider numerous attributes in evaluating whether the costs to manufacture a particular product should be capitalized as an asset. We assess the regulatory approval process and where the particular product stands in relation to that approval process, including any known safety or efficacy concerns, potential labeling restrictions and other impediments to approval. We evaluate our anticipated research and development initiatives and constraints relating to the product and the indication in which it will be used. We consider our manufacturing environment including our supply chain in determining logistical constraints that could hamper approval or commercialization. We consider the shelf life of the product in relation to the expected timeline for approval and we consider patent related or contract issues that may prevent or delay commercialization. We also base our judgment on the viability of commercialization, trends in the marketplace and market acceptance criteria. Finally, we consider the reimbursement strategies that may prevail with respect to the product and assess the economic benefit that we are likely to realize. We expense previously capitalized costs related to pre-approval inventory upon a change in such judgment, due to, among other potential factors, a denial or delay of approval by necessary regulatory bodies.

As of December 31, 2011 and 2010, the carrying value of our inventory did not include any significant costs associated with products that had not yet received regulatory approval.

Obsolescence and Unmarketable Inventory

We periodically review our inventories for excess or obsolete inventory and write-down obsolete or otherwise unmarketable inventory to its estimated net realizable value. If the actual net realizable value is less than that estimated by us, or if it is determined that inventory utilization will further diminish based on estimates of demand, additional inventory write-downs may be required. Additionally, our products are subject to strict quality control and monitoring which we perform throughout the manufacturing process. In the event that certain batches or units of product no longer meet quality specifications or become obsolete due to expiration, we will record a charge to cost of sales to write-down any obsolete or otherwise unmarketable inventory to its estimated net realizable value. In all cases product inventory is carried at the lower of cost or its estimated net realizable value. Amounts written-down to unmarketable inventory are charged to cost of sales, excluding amortization of acquired intangible assets.

Marketable Securities and Other Investments

Marketable Debt Securities

Available-for-sale debt securities are recorded at fair market value and unrealized gains and losses are included in accumulated other comprehensive income (loss) in equity, net of related tax effects, unless the security has experienced a credit loss, we have determined that we have the intent to sell the security or we have determined that it is more likely than not that we will have to sell the security before its expected recovery. Realized gains and losses are reported in other income (expense), net, on a specific identification basis.

Strategic Investments

As part of our business development efforts, we will, from time to time, invest in equity securities of certain biotechnology companies. These investments are known as strategic investments and are classified as available-for-sale and accounted for as marketable equity investments or as cost investments based upon our ownership percentage and other factors that suggest we have significant influence and are included in investments and other assets within our consolidated balance sheet. When assessing whether a decline in the fair value of a strategic investment below our cost basis is other-than-temporary, we consider the fair market value of the security, the duration of the security’s decline, and prospects for the underlying business, including favorable or adverse clinical trial results, new product initiatives and new collaborative agreements with the companies in which we have invested.

Non-Marketable Equity Securities

We also invest in equity securities of companies whose securities are not publicly traded and where fair value is not readily available. These investments are recorded using either the cost method or the equity method of accounting, depending on our ownership percentage and other factors that suggest we have significant influence. We monitor these investments to evaluate whether any decline in their value has occurred that would be other-than-temporary, based on the implied value of recent company financings, public market prices of comparable companies, and general market conditions and are included in investments and other assets within our consolidated balance sheet.

Evaluating Investments for Other-than-Temporary Impairments

We conduct periodic reviews to identify and evaluate each investment that has an unrealized loss, in accordance with the meaning of other-than-temporary impairment and its application to certain investments. An unrealized loss exists when the current fair value of an individual security is less than its amortized cost basis. Unrealized losses on available-for-sale securities that are determined to be temporary, and not related to credit loss, are recorded, net of tax, in accumulated other comprehensive income.

For available-for-sale debt securities with unrealized losses, management performs an analysis to assess whether we intend to sell or whether we would more likely than not be required to sell the security before the expected recovery of the amortized cost basis. Where we intend to sell a security, or may be required to do so, the security’s decline in fair value is deemed to be other-than-temporary and the full amount of the unrealized loss is reflected within earnings as an impairment loss.

Regardless of our intent to sell a security, we perform additional analysis on all securities with unrealized losses to evaluate losses associated with the creditworthiness of the security. Credit losses are identified where we do not expect to receive cash flows sufficient to recover the amortized cost basis of a security.

For equity securities, when assessing whether a decline in fair value below our cost basis is other-than-temporary, we consider the fair market value of the security, the duration of the security’s decline, and the financial condition of the issuer. We then consider our intent and ability to hold the equity security for a period of time sufficient to recover our carrying value. Where we have determined that we lack the intent and ability to hold an equity security to its expected recovery, the security’s decline in fair value is deemed to be other-than-temporary and is reflected within earnings as an impairment loss.

Property, Plant and Equipment

Property, plant and equipment are carried at cost, subject to review for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. The cost of normal, recurring, or periodic repairs and maintenance activities related to property, plant and equipment are expensed as incurred. The cost for planned major maintenance activities, including the related acquisition or construction of assets, is capitalized if the repair will result in future economic benefits.

Interest costs incurred during the construction of major capital projects are capitalized until the underlying asset is ready for its intended use, at which point the interest costs are amortized as depreciation expense over the life of the underlying asset. We also capitalize certain direct and incremental costs associated with the validation effort required for licensing by regulatory agencies of manufacturing equipment for the production of a commercially approved drug. These costs include primarily direct labor and material and are incurred in preparing the equipment for its intended use. The validation costs are amortized over the life of the related equipment.

In addition, we capitalize certain internal use computer software development costs. If the software is an integral part of production assets, these costs are included in machinery and equipment and are amortized on a straight-line basis over the estimated useful lives of the related software, which generally range from three to five years.

We generally depreciate or amortize the cost of our property, plant and equipment using the straight-line method over the estimated useful lives of the respective assets, which are summarized as follows:

When we dispose of property, plant and equipment, we remove the associated cost and accumulated depreciation from the related accounts on our consolidated balance sheet and include any resulting gain or loss in our consolidated statement of income.

Intangible Assets

Our intangible assets consist of patents, licenses, core developed technology, in-process research and development acquired after January 1, 2009, trademarks, trade names, assembled workforce and other distribution rights. The majority of our intangible assets were recorded in connection with the merger of Biogen, Inc. and IDEC Pharmaceuticals Corporation in 2003. Our intangible assets are recorded at fair value at the time of their acquisition and are stated within our consolidated balance sheets net of accumulated amortization and impairments.

We amortize intangible assets over their estimated useful lives using the economic use method if anticipated future cash flows can be reasonably estimated; the straight-line method is used when cash flows cannot be reasonably estimated. Our amortization policy reflects the pattern that the economic benefits of the intangible assets are consumed. The useful lives of our intangible assets are primarily based on the legal or contractual life of the underlying patent or contract, which does not include additional years for the potential extension or renewal of the contract or patent. Intangible assets related to patents, licenses, core developed technology, assembled workforce, and other distribution rights are amortized over their remaining estimated useful lives. Intangible assets related to trademarks, trade names and in-process research and development prior to commercialization are not amortized because they have indefinite lives, but they are subject to review for impairment. We review our intangible assets with indefinite lives for impairment annually, as of October 31, and whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable.

Our most significant intangible asset is the core technology related to our AVONEX product. Our amortization policy reflects our belief that the economic benefit of our core technology is consumed as revenue is generated from AVONEX. We refer to this amortization methodology as the economic consumption model, which involves calculating a ratio of actual current period sales to total anticipated sales for the life of the product and applying this ratio to the carrying amount of the intangible asset. An analysis of the anticipated lifetime revenue of AVONEX is performed at least annually during our long range planning cycle, and this analysis serves as the basis for the calculation of our economic consumption amortization model. We believe this process has allowed us to reliably determine the best estimate of the pattern in which we will consume the economic benefits of our core technology intangible asset.

Acquired In-process Research and Development (IPR&D)

Acquired IPR&D represents the fair value assigned to research and development assets that we acquire that have not been completed at the date of acquisition. The value assigned to acquired IPR&D is determined by estimating the costs to develop the acquired technology into commercially viable products, estimating the resulting revenue from the projects, and discounting the net cash flows to present value. The revenue and costs projections used to value acquired IPR&D were, as applicable, reduced based on the probability of developing a new drug. Additionally, the projections considered the relevant market sizes and growth factors, expected trends in technology, and the nature and expected timing of new product introductions by us and our competitors. The resulting net cash flows from such projects are based on management’s estimates of cost of sales, operating expenses, and income taxes from such projects. The rates utilized to discount the net cash flows to their present value were commensurate with the stage of development of the projects and uncertainties in the economic estimates used in the projections described above.

We measured acquired IPR&D in business combinations completed prior to January 1, 2009, at fair value and expensed it on acquisition date if that technology lacked an alternative future use, or capitalized it as an intangible asset if certain criteria were met; however, effective January 1, 2009, if we are purchasing a business, the acquired IPR&D is measured at fair value, capitalized as an intangible asset and tested for impairment at least annually until commercialization, after which time the IPR&D is amortized over its estimated useful life. If we acquire an asset or group of assets that do not meet the definition of a business under applicable accounting standards, then the acquired IPR&D is expensed on its acquisition date. Future costs to develop these assets are recorded to expense as they are incurred if the technology lacks alternative future uses.

We review amounts capitalized as in-process research and development for impairment at least annually, as of October 31, and whenever events or changes in circumstances indicate that the carrying value of the assets might not be recoverable. In the event the carrying value of the assets are not expected to be recovered, the assets are written down to their estimated fair values.

Impairment of Long-Lived Assets

Long-lived assets to be held and used, including property, plant and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets or asset group may not be recoverable.

Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written-down to their estimated fair values. Long-lived assets to be disposed of are carried at fair value less costs to sell.

Goodwill

Goodwill relates largely to amounts that arose in connection with the merger of Biogen, Inc. and IDEC Pharmaceuticals Corporation and represents the difference between the purchase price and the fair value of the identifiable tangible and intangible net assets when accounted for using the purchase method of accounting. Goodwill is not amortized, but is subject to periodic review for impairment. Goodwill is reviewed annually, as of October 31, and whenever events or changes in circumstances indicate that the carrying value of the goodwill might not be recoverable.

We apply a two-step impairment test. In the first step, we compare the fair value of our reporting unit to its carrying value. If the carrying value of the net assets assigned to the reporting unit exceeds the fair value of our reporting unit, then the second step of the impairment test is performed in order to determine the implied fair value of our reporting unit’s goodwill. If the carrying value of our reporting unit’s goodwill exceeds its implied fair value, then the company records an impairment loss equal to the difference. As described in Note 25, Segment Information to these consolidated financial statements, we operate in one business segment which we consider our only reporting unit.

In September 2011, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2011-08, “Intangibles — Goodwill and Other (Topic 350): Testing Goodwill for Impairment” (ASU 2011-08). This newly issued accounting standard allows an entity the option to first assess qualitative factors to determine whether it is necessary to perform the current two-step impairment test. If an entity believes, as a result of its qualitative assessment, that it is more-likely-than-not that the fair value of a reporting unit is less than its carrying amount, the quantitative two-step impairment test is required; otherwise, no further testing is required. These amendments do not change the current guidance for testing other indefinite-lived intangible assets for impairment. This ASU is effective for annual and interim goodwill impairment tests performed for fiscal years beginning after December 15, 2011, which for Biogen Idec means January 1, 2012. Early adoption is permitted; however, we have not elected to do so. The adoption of this statement will not impact our financial position or results of operations.

Derivative Instruments and Hedging Activities

We recognize all derivative instruments as either assets or liabilities at fair value in our consolidated balance sheets. Changes in the fair value of derivatives are recorded each period in current earnings or accumulated other comprehensive income (loss), depending on whether a derivative is designated as part of a hedge transaction and, if it is, the type of hedge transaction. We classify the cash flows from these instruments in the same category as the cash flows from the hedged items. We do not hold or issue derivative instruments for trading or speculative purposes.

We assess, both at inception and on an ongoing basis, whether the derivatives that are used in hedging transactions are highly effective in offsetting the changes in cash flows or fair values of the hedged items. We also assess hedge ineffectiveness on a quarterly basis and record the gain or loss related to the ineffective portion to current earnings to the extent significant. If we determine that a forecasted transaction is no longer probable of occurring, we discontinue hedge accounting for the affected portion of the hedge instrument, and any related unrealized gain or loss on the contract is recognized in current earnings.

Translation of Foreign Currencies

The functional currency for most of our foreign subsidiaries is their local currency. For the Company’s non-U.S. subsidiaries that transact in functional currency other than the U.S. dollar, assets and liabilities are translated at current rates of exchange at the balance sheet date. Income and expense items are translated at the average foreign exchange rates for the period. Adjustments resulting from the translation of the financial statements of our foreign operations into U.S. dollars are excluded from the determination of net income and are recorded in accumulated other comprehensive income, a separate component of equity. For subsidiaries where the functional currency differs from the local currency, non-monetary assets and liabilities are translated at the rate of exchange in effect on the date assets were acquired while monetary assets and liabilities are translated at current rates of exchange as of the balance sheet date. Income and expense items are translated at the average foreign currency rates for the period. Translation adjustments of these subsidiaries are included in net income.

Accounting for Share-Based Compensation

Our share-based compensation programs grant awards which have included stock options, restricted stock units which vest based on stock performance known as market stock units (MSUs), performance-vested restricted stock units which will be settled in cash (CSPSs), performance-vested restricted stock units which settle in shares (PVRSUs), time-vested restricted stock units (RSUs) and shares issued under our employee stock purchase plan (ESPP). We charge the estimated fair value of awards against income over the requisite service period, which is generally the vesting period. Where awards are made with non-substantive vesting periods (for instance, where a portion of the award vests upon retirement eligibility), we estimate and recognize expense based on the period from the grant date to the date on which the employee is retirement eligible.

The fair values of our stock option grants are estimated as of the date of grant using a Black-Scholes option valuation model and reflect estimated forfeitures. The estimated fair values of the stock options are then expensed over the options’ vesting periods.

The fair values of our RSUs are based on the market value of our stock on the date of grant. Compensation expense for RSUs is recognized over the applicable service period, adjusted for the effect of estimated forfeitures.

We apply an accelerated attribution method to recognize stock based compensation expense, net of estimated forfeitures, when accounting for our MSUs. The probability of actual shares expected to be earned is considered in the grant date valuation, therefore the expense will not be adjusted to reflect the actual units earned.

We apply an accelerated attribution method to recognize stock based compensation expense when accounting for our CSPSs and the fair value of the liability is remeasured at the end of each reporting period through expected cash settlement. Compensation expense associated with CSPSs is based upon the stock price and the number of units expected to be earned after assessing the probability that certain performance criteria will be met and the associated targeted payout level that is forecasted will be achieved, net of estimated forfeitures. Cumulative adjustments are recorded each quarter to reflect changes in the stock price and estimated outcome of the performance-related conditions until the date results are determined and settled.

We apply an accelerated attribution method to recognize stock based compensation expense when accounting for our PVRSUs. The number of units reflected as granted represents the target number of shares that are eligible to vest in full or in part and are earned subject to the attainment of certain performance criteria established at the beginning of the performance period. Compensation expense associated with these units is initially based upon the number of shares expected to vest after assessing the probability that certain performance criteria will be met and the associated targeted payout level that is forecasted will be achieved, net of estimated forfeitures. Cumulative adjustments are recorded quarterly to reflect subsequent changes in the estimated outcome of performance-related conditions until the date results are determined.

The purchase price of common stock under our ESPP is equal to 85% of the lower of (i) the market value per share of the common stock on the participant’s entry date into an offering period or (ii) the market value per share of the common stock on the purchase date. However, for each participant whose entry date is other than the start date of the offering period, the amount shall in no event be less than the market value per share of the common stock as of the beginning of the related offering period. The fair value of the discounted purchases made under our ESPP is calculated using the Black-Scholes model. The fair value of the look-back provision plus the 15% discount is recognized as compensation expense over the purchase period. We apply a graded vesting approach since our ESPP provides for multiple purchase periods and is, in substance, a series of linked awards.

Research and Development Expenses

Research and development expenses consist of upfront fees and milestones paid to collaborators and expenses incurred in performing research and development activities, including compensation and benefits, facilities expenses, overhead expenses, clinical trial and related clinical manufacturing expenses, fees paid to clinical research organizations (CROs) and other outside expenses. Research and development expenses are expensed as incurred. Payments we make for research and development services prior to the services being rendered are recorded as prepaid assets on our consolidated balance sheets and are expensed as the services are provided.

From time to time, we enter into development agreements in which we share expenses with a collaborative partner. We record payments received from our collaborative partners for their share of the development costs as a reduction of research and development expense, except as discussed within Note 20, Collaborations to these consolidated financial statements. Expenses incurred by Genentech in the development of RITUXAN are not recorded as research and development expense, but rather reduce our share of co-promotion profits recorded as a component of unconsolidated joint business revenues.

Selling, General and Administrative Expenses

Selling, general and administrative expenses are primarily comprised of compensation and benefits associated with sales and marketing, finance, human resources, legal and other administrative personnel, outside marketing, advertising and legal expenses and other general and administrative costs.

Advertising costs are expensed as incurred. For the years ended December 31, 2011, 2010 and 2009, advertising costs totaled $45.3 million, $35.3 million and $26.5 million, respectively.

Income Taxes

The provision for income taxes includes federal, state, local and foreign taxes. Income taxes are accounted for under the liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences of temporary differences between the financial statement carrying amounts and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which the temporary differences are expected to be recovered or settled. We evaluate the realizability of our deferred tax assets and establish a valuation allowance when it is more likely than not that all or a portion of deferred tax assets will not be realized.

We account for uncertain tax positions using a “more-likely-than-not” threshold for recognizing and resolving uncertain tax positions. We evaluate uncertain tax positions on a quarterly basis and consider various factors, including, but not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, new audit activity and changes in facts or circumstances related to a tax position. We also accrue for potential interest and penalties, related to unrecognized tax benefits in income tax expense.

Contingencies

We are currently involved in various claims and legal proceedings. We account for potential litigation losses in accordance with FASB Accounting Standards Codification (ASC) No. 450, Contingencies (ASC 450). Under ASC 450, loss contingency provisions are recorded if the potential loss from any claim, asserted or unasserted, or legal proceeding is considered probable and the amount can be reasonably estimated or a range of loss can be determined. These accruals represent management’s best estimate of probable loss, as defined by ASC 450. Disclosure also is provided when it is reasonably possible that a loss will be incurred or when it is reasonably possible that the amount of a loss will exceed the recorded provision. On a quarterly basis, we review the status of each significant matter and assess its potential financial exposure. Significant judgment is required in both the determination of probability and the determination as to whether an exposure is reasonably estimable. Because of uncertainties related to these matters, accruals are based only on the best information available at the time. As additional information becomes available, we reassess the potential liability related to pending claims and litigation and may revise our estimates. These revisions in the estimates of the potential liabilities could have a material impact on our consolidated results of operations and financial position.

Restructuring Charges

We have made estimates and judgments regarding the amount and timing of our restructuring expense and liability, including current and future period termination benefits and other exit costs to be incurred when related actions take place. We have also assessed the recoverability of certain long-lived assets employed in the business and, in certain instances shortened the expected useful life of the assets based on changes in their expected use. When we determine that the useful lives of assets are shorter than we had originally estimated, we record additional depreciation to reflect the assets’ new shorter useful lives. Severance and other related costs and asset-related charges are reflected within our consolidated statement of income as a component of total restructuring charges incurred. Actual results may differ from these estimates. For additional information related to our recent restructuring efforts, please read Note 3, Restructuring, to these consolidated financial statements.

Earnings per Share

Basic earnings per share is computed using the two-class method. Under the two-class method, undistributed net income is allocated to common stock and participating securities based on their respective rights to share in dividends. We have determined that our preferred shares meet the definition of participating securities and, to the extent any are outstanding during a period, have allocated a portion of net income to our preferred shares on a pro rata basis. Net income allocated to preferred shares is excluded from the calculation of basic earnings per share. For basic earnings per share, net income available to holders of common stock is divided by the weighted average number of shares of common stock outstanding. For purposes of calculating diluted earnings per share, net income is adjusted for the after-tax amount of net income allocable to preferred shares, and the denominator includes both the weighted average number of shares of common stock outstanding and potential dilutive shares of common stock from stock options, unvested restricted stock awards, restricted stock units and other convertible securities, to the extent they are dilutive.

New Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, we believe that the impact of recently issued standards that are not yet effective will not have a material impact on our financial position or results of operations upon adoption.

In December 2011, the FASB issued ASU 2011-11, Balance Sheet (Topic 210): Disclosures about Offsetting Assets and Liabilities (ASU 2011-11). This newly issued accounting standard requires an entity to disclose both gross and net information about instruments and transactions eligible for offset in the statement of financial position as well as instruments and transactions executed under a master netting or similar arrangement and was issued to enable users of financial statements to understand the effects or potential effects of those arrangements on its financial position. This ASU is required to be applied retrospectively and is effective for fiscal years, and interim periods within those years, beginning on or after January 1, 2013. As this accounting standard only requires enhanced disclosure, the adoption of this standard is not expected to have an impact our financial position or results of operations.

In June 2011, the FASB issued ASU No. 2011-05, “Comprehensive Income (Topic 220): Presentation of Comprehensive Income” (ASU 2011-05). This newly issued accounting standard (1) eliminates the option to present the components of other comprehensive income as part of the statement of changes in stockholders’ equity; (2) requires the consecutive presentation of the statement of net income and other comprehensive income; and (3) requires an entity to present reclassification adjustments on the face of the financial statements from other comprehensive income to net income. The amendments in this ASU do not change the items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income nor do the amendments affect how earnings per share is calculated or presented. In December 2011, the FASB issued ASU No. 2011-12, Deferral of the Effective Date for Amendments to the Presentation of Reclassifications of Items Out of Accumulated Other Comprehensive Income in Accounting Standards Update No. 2011-05, which defers the requirement within ASU 2011-05 to present on the face of the financial statements the effects of reclassifications out of accumulated other comprehensive income on the components of net income and other comprehensive income for all periods presented. During the deferral, entities should continue to report reclassifications out of accumulated other comprehensive income consistent with the presentation requirements in effect prior to the issuance of ASU 2011-05. These ASUs are required to be applied retrospectively and are effective for fiscal years, and interim periods within those years, beginning after December 15, 2011, which for Biogen Idec means January 1, 2012. As these accounting standards do not change the items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income, the adoption of these standards is not expected to have an impact on our financial position or results of operations.

In May 2011, the FASB issued ASU No. 2011-04, “Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRSs” (ASU 2011-04). This newly issued accounting standard clarifies the application of certain existing fair value measurement guidance and expands the disclosures for fair value measurements that are estimated using significant unobservable (Level 3) inputs. This ASU is effective on a prospective basis for annual and interim reporting periods beginning on or after December 15, 2011, which for Biogen Idec means January 1, 2012. The adoption of this standard is not expected to have a material impact on our financial position or results of operations.

2.    Acquisitions

Noncontrolling Interest in Joint Ventures

On September 6, 2011, we completed the purchase of the noncontrolling interest in our joint venture investments in Biogen Dompé SRL and Biogen Dompé Switzerland GmbH, our respective sales affiliates in Italy and Switzerland, from our joint venture partners, Dompé Farmaceutici SpA and Dompé International SA, respectively. This transaction was funded from our existing cash on hand and has been accounted for as the acquisition of a noncontrolling interest. The purchase price of these shares was comprised of cash payments totaling $152.9 million plus up to $42.5 million in contingent consideration payable upon the achievement of commercial and regulatory milestones using exchange rates at the time of the transaction. As these amounts reflect payments to acquire a noncontrolling interest, these payments and the accrual of a liability related to the contingent consideration were recorded as a reduction in the noncontrolling interest for these entities with the remainder to additional paid in capital.

Upon acquisition, we recorded a liability of $38.8 million representing the acquisition date fair value of the contingent consideration. This amount was estimated through a valuation model that incorporates probability weighted assumptions relating to the achievement of these milestones and thus the likelihood of us making payments. Subsequent changes in the fair value of this obligation will be recognized as adjustments to contingent consideration within our consolidated statements of income. For additional information related to our valuation of this obligation, please read Note 8, Fair Value Measurements to these consolidated financial statements.

In connection with our purchase of the noncontrolling interest in our joint venture investment in Biogen Dompé SRL, we entered into a credit assignment agreement with Dompé Farmaceutici SpA. Under the terms of this agreement, Dompé Farmaceutici SpA purchased all of Biogen Dompé SRL’s outstanding receivables as of June 30, 2011, adjusted for cash received through September 5, 2011, for $104.6 million. We have no retained interests in the receivables and have accounted for this transaction as a sale. The carrying value of these receivables exceeded their fair value, which was determined by management using significant inputs not observable in the market and thus represents a Level 3 fair value measurement, and accordingly we recognized a loss of $1.8 million upon their disposition.

In addition, balances outstanding under Biogen Dompé SRL’s credit line from Dompé Farmaceutici SpA, as described in Note 12, Indebtedness to these consolidated financial statements, were repaid in September 2011.

Biogen Idec International Neuroscience GmbH

In December 2010, we acquired 100% of the stock of Biogen Idec International Neuroscience GmbH (BIN), formerly Panima Pharmaceuticals AG, an affiliate of Neurimmune AG. The purchase price was comprised of a $32.5 million cash payment plus up to $395.0 million in contingent consideration payable upon the achievement of development milestones. BIN is a business involved in the discovery of antibodies designed to treat neurological disorders. Upon acquisition, we recorded a liability of $81.2 million representing the acquisition date fair value of the contingent consideration. Subsequent changes in the fair value of this obligation are recognized as adjustments to contingent consideration within our consolidated statements of income. We allocated $110.9 million and $25.6 million of the total purchase price to acquired IPR&D and goodwill, respectively. The amount allocated to acquired IPR&D represented the fair value of the IPR&D programs acquired. The goodwill recognized is primarily attributable to establishing a deferred tax liability for the acquired IPR&D asset, which is not deductible for income tax purposes. For additional information related to our valuation of our contingent consideration obligation, please read Note 8, Fair Value Measurements to these consolidated financial statements.

Biogen Idec Hemophilia Inc.

In connection with our acquisition of Biogen Idec Hemophilia Inc. (BIH), formerly Syntonix Pharmaceuticals, Inc. (Syntonix), in January 2007, we agreed to pay up to an additional $80.0 million if certain milestone events associated with the development of BIH’s lead product, long-lasting recombinant Factor IX, a product for the treatment of hemophilia B, are achieved. The first $40.0 million contingent payment was achieved in the first quarter of 2010 upon initiation of patient enrollment in a registrational trial of Factor IX. We recorded this payment as a charge to acquired in-process research and development within our consolidated statement of income in 2010, in accordance with the accounting standards applicable to business combinations when we acquired BIH.

An additional $20.0 million contingent payment will occur if prior to the tenth anniversary of the closing date, the FDA grants approval of a Biologic License Application for Factor IX. A second $20.0 million contingent payment will occur if prior to the tenth anniversary of the closing date, a marketing authorization is granted by the EMA for Factor IX. These payments will be capitalized as an intangible asset when the related milestones are achieved.

3.    Restructuring

In November 2010, we announced a number of strategic, operational, and organizational initiatives designed to provide a framework for the future growth of our business and realign our overall structure to become a more efficient and cost effective organization. As part of this initiative:

Costs associated with our workforce reduction primarily relate to employee severance and benefits. Facility consolidation costs are primarily comprised of charges associated with closing these facilities, related lease obligations and additional depreciation recognized when the expected useful lives of certain assets have been shortened due to the consolidation and closing of related facilities and the discontinuation of certain research and development programs. As of December 31, 2011, substantially all restructuring charges have been incurred and paid. We incurred $19.0 million of these charges in 2011, of which $12.8 million were related to our workforce reduction and $6.2 million related to the consolidation of our facilities. During the fourth quarter of 2010, we incurred $75.2 million of these charges, of which $67.2 million were related to our workforce reduction and $8.0 million were related to the consolidation of our facilities.

The following table summarizes the activity of our restructuring liability:

4.    Revenue Reserves

Reserves for Discounts and Allowances

An analysis of the amount of, and change in, reserves is summarized as follows:

The total reserves above, included in our consolidated balance sheets, are summarized as follows:

5.    Accounts Receivable

Our accounts receivable primarily arise from product sales in the U.S. and Europe and mainly represent amounts due from our wholesale distributors, public hospitals and other government entities. The majority of our accounts receivable have standard payment terms which are generally between 30 and 90 days. We monitor the financial performance and credit worthiness of our large customers so that we can properly assess and respond to changes in their credit profile. We provide reserves against trade receivables for estimated losses that may result from a customer’s inability to pay. Amounts determined to be uncollectible are charged or written-off against the reserve. To date, such losses have not exceeded management’s estimates.

Concentrations of credit risk with respect to receivables, which are typically unsecured, are limited due to the wide variety of customers and markets using our products, as well as their dispersion across many different geographic areas. We monitor economic conditions, including volatility associated with international economies, and related impacts on the relevant financial markets and our business, especially in light of sovereign credit issues. The credit and economic conditions within Italy, Spain, Portugal and Greece, among other members of the European Union, have continued to deteriorate. These conditions have increased, and may continue to increase, the average length of time that it takes to collect on our accounts receivable outstanding in these countries.

Our net accounts receivable balances from product sales in these countries are summarized as follows:

Approximately $56.0 million and $45.0 million of the aggregated balances for these countries were overdue more than one year as of December 31, 2011 and December 31, 2010, respectively. Amounts included as a component of investments and other assets within our consolidated balance sheets represent amounts that are expected to be collected beyond one year.

In connection with our purchase of the noncontrolling interest in our joint venture investments in Biogen Dompé SRL, we entered into a credit assignment agreement with Dompé Farmaceutici SpA. Under the terms of this agreement, Dompé Farmaceutici SpA purchased all of Biogen Dompé SRL’s outstanding receivables as of June 30, 2011, adjusted for cash received through September 5, 2011, for $104.6 million. We retained no interests in these receivables and accounted for this transaction as a sale recognizing a loss of $1.8 million upon their disposition. For additional information related to these transactions, please read Note 2, Acquisitions to these consolidated financial statements. As of December 31, 2011, our accounts receivable balances in Italy totaled $68.1 million, all of which resulted from sales of product subsequent to June 30, 2011.

6.    Inventory

The components of inventory are summarized as follows:

The components of inventory by product are summarized as follows:

Amounts written down related to excess, obsolete or unmarketable inventory are charged to cost of sales, and totaled $25.4 million, $11.8 million, and $16.9 million for the years ended December 31, 2011, 2010, and 2009, respectively.

7.    Intangible Assets and Goodwill

Intangible Assets

Intangible assets, net of accumulated amortization, impairment charges and adjustments, are summarized as follows:

Total intangible assets was unchanged as of December 31, 2011 compared to December 31, 2010, excluding the impact of amortization and amounts recorded in connection with the license agreements for FAMPYRA and the JC virus assay described below. In December 2010, we completed our acquisition of BIN and allocated a $110.9 million of the purchase price to acquired IPR&D. For additional information related to this transaction, please read Note 2, Acquisitions to these consolidated financial statements.

Amortization of acquired intangible assets totaled $208.6 million, $208.9 million, and $289.8 million for the years ended December 31, 2011, 2010 and 2009, respectively. Amortization for acquired intangible assets is expected to be in the range of approximately $160.0 million to $200.0 million annually through 2016.

AVONEX Core Technology Asset

Our most significant intangible asset is the core technology related to our AVONEX product. The net book value of this asset as of December 31, 2011 was $1,192.1 million. Amortization of our core acquired intangible asset related to AVONEX is expected to be in the range of approximately $100.0 million to $150.0 million annually through 2016.

FAMPYRA

In July 2011, the European Commission (EC) granted a conditional marketing authorization for FAMPYRA in the E.U., which triggered a $25.0 million milestone payment. This payment was made to Acorda Therapeutics, Inc. (Acorda) in the third quarter of 2011 and was capitalized as an intangible asset.

Under the terms of our 2009 collaboration and license agreement, we will pay Acorda additional milestones based on new indications and ex-U.S. net sales. The next expected milestone would be $15.0 million, due when ex-U.S. net sales reach $100.0 million over a period of four consecutive quarters. We will capitalize these milestones upon achievement as an intangible asset. Amortization will utilize an economic consumption model that will be based on an estimate of all of the probable payments we expect to make as contingent consideration, such as sales-based milestones, for entering into the license agreement.

For additional information related to our collaboration with Acorda, please read Note 20, Collaborations to these consolidated financial statements.

JC Virus Assay

In the first quarter of 2011, we licensed rights for the diagnostic and therapeutic application of recombinant virus-like particles, known as VP1 proteins, to detect antibodies of the JC virus (JCV) in serum or blood. Under the terms of this license, we expect to make payments totaling approximately $58.9 million through 2016. These payments include upfront and milestone payments as well as the greater of an annual maintenance fee or usage-based royalty payment. As of December 31, 2011, we recognized an intangible asset in the amount of $19.2 million, reflecting the total of upfront payments made and other time-based milestone payments. We will further capitalize additional payments due under this arrangement as an intangible asset upon achievement. Amortization will utilize an economic consumption model that will be based on an estimate of all of the probable payments we expect to make in relation to the total number of JCV assay tests performed through 2016.

Goodwill

The following table provides a roll forward of the changes in goodwill:

As of December 31, 2011, we had no accumulated impairment losses related to goodwill.

In December 2010, we completed our acquisition of BIN and allocated a $25.6 million of the purchase price to goodwill. For additional information related to this transaction, please read Note 2, Acquisitions to these consolidated financial statements. During 2010, we also recorded a decrease to goodwill of $17.9 million to establish a deferred tax asset that existed at the time of the merger of Biogen, Inc. and IDEC Pharmaceuticals Corporation in 2003.

8.    Fair Value Measurements

The tables below present information about our assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2011 and December 31, 2010, and indicate the fair value hierarchy of the valuation techniques we utilized to determine such fair value: