|
Valuation of debt and equity investments and certain liabilities (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | |
|---|---|---|
|
Dec. 31, 2011
|
Dec. 31, 2010
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Auction Rate Securities Assets [Member]
|
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| Changes in fair value during the period pre tax [Abstract] | ||
| Beginning balance | $ 257 | $ 458 |
| Change in fair value of contingent consideration - included in operating profit | 0 | 0 |
| Change in unrealized loss – included in AOCI | (1) | 10 |
| Redemptions and sales | (122) | (188) |
| Transfers into Level 2 | (23) | |
| Ending balance | 134 | 257 |
|
Contingent Consideration [Member]
|
||
| Changes in fair value during the period pre tax [Abstract] | ||
| Beginning balance | 8 | 18 |
| Change in fair value of contingent consideration - included in operating profit | (8) | (10) |
| Change in unrealized loss – included in AOCI | 0 | 0 |
| Redemptions and sales | 0 | 0 |
| Transfers into Level 2 | 0 | |
| Ending balance | $ 0 | $ 8 |