LONG-TERM OBLIGATIONS

Financing Arrangements

The following table summarizes the carrying amount of our borrowings under various financing arrangements (in thousands):



Type of Borrowing	Description	Issue Date	Due Date	Interest Rate	March 31, 2012		December 31, 2011
Convertible Senior	May 2013 Notes	April 2006	May 2013	0.625%	$	614,791	$	607,036
Convertible Senior	May 2014 Notes	July 2010	May 2014	1.00%	1,188,594		1,181,525
Convertible Senior	May 2016 Notes	July 2010	May 2016	1.625%	1,138,538		1,132,293
Senior Unsecured	April 2021 Notes	March 2011	April 2021	4.50%	992,280		992,066
Senior Unsecured	December 2014 Notes	December 2011	December 2014	2.40%	749,157		749,078
Senior Unsecured	December 2016 Notes	December 2011	December 2016	3.05%	698,921		698,864
Senior Unsecured	December 2021 Notes	December 2011	December 2021	4.40%	1,247,212		1,247,138
Senior Unsecured	December 2041 Notes	December 2011	December 2041	5.65%	997,753		997,734
Term Loan Facility	Term Loan	January 2012	January 2015	Variable	650,000		—
Credit Facility	Short-Term Revolver	January 2012	January 2013	Variable	400,000		—
Credit Facility	Five-Year Revolver	January 2012	January 2017	Variable	750,000		—
Total debt, net					$	9,427,246	$	7,605,734
Less current portion					1,350,000		—
Total long-term debt, net					$	8,077,246	$	7,605,734

Credit Facilities

We were eligible to borrow up to an aggregate of $1.25 billion in revolving credit loans under an amended and restated credit agreement that we entered into in 2007. The credit agreement also included a sub-facility for swing-line loans and letters of credit. As of December 31, 2011, we had $4.0 million in letters of credit outstanding under the credit agreement. In January 2012, we fully repaid the outstanding obligations under this credit agreement and terminated the credit agreement.

In January 2012, in conjunction with our acquisition of Pharmasset, we entered into a five-year $1.25 billion revolving credit facility credit agreement (the Five-Year Revolving Credit Agreement), a $750.0 million short-term revolving credit facility credit agreement (the Short-Term Revolving Credit Agreement) and a $1.00 billion term loan facility (the Term Loan Credit Agreement). We borrowed $750.0 million under the Five-Year Revolving Credit Agreement, $400.0 million under the Short-Term Revolving Credit Agreement and $1.00 billion under the Term Loan Credit Agreement, upon the close of the acquisition. In March 2012, we repaid $350.0 million of the outstanding debt under the Term Loan Credit Agreement.

All three credit agreements contain customary representations, warranties, affirmative, negative and financial maintenance covenants and events of default. The loans bear interest at either (i) the Eurodollar Rate plus the Applicable Margin or (ii) the Base Rate plus the Applicable Margin, each as defined in the applicable credit agreement. We may reduce the commitments and may prepay loans under any of these agreements in whole or in part at any time without premium or penalty.

The Five-Year Revolving Credit Agreement was inclusive of a $30.0 million swing line loan sub-facility and a $25.0 million letter of credit sub-facility. As of March 31, 2012, we had $4.0 million in letters of credit outstanding under the Five-Year Revolving Credit Agreement. The Five-Year Revolving Credit Agreement will terminate and all unpaid borrowings thereunder shall be due and payable in January 2017. The Short-Term Revolving Credit Agreement will terminate and all unpaid borrowings thereunder shall be due and payable in January 2013; however, at our request, the maturity date may be extended until January 2014. All principal repayment installments under the Term Loan Credit Agreement will be due and payable as specified in the Term Loan Credit Agreement, with the final principal installment payment due and payable in January 2015.