Stockholders' Equity (Narrative) (Details) (USD $) Share data in Millions, except Per Share data | 3 Months Ended | 9 Months Ended | 1 Months Ended | |
|---|---|---|---|---|
Sep. 30, 2011 | Sep. 30, 2011 | May 31, 2010
Stock Repurchase Program; $5B, May-10, 3-Year [Member] | Jan. 31, 2011
Stock Repurchase Program; $5B, Jan-11, 3-year [Member] | |
| Stockholders' Equity [Line Items] | ||||
| Amount of stock retired under the stock repurchase programs | $ 883,600,000 | $ 2,160,000,000 | ||
| Number of shares retired under the stock repurchase programs | 22.4 | 54.2 | 135.5 | |
| Authorized common stock repurchase program | 5,000,000,000 | 5,000,000,000 | ||
| Remaining authorized amount of stock repurchases | 4,820,000,000 | |||
| Average purchase price per share of the stock repurchased and retired under the stock repurchase program | $ 36.89 | |||
| Decrease in common stock and APIC | 168,200,000 | |||
| Excess of purchase price over par value charged against retained earnings | $ 2,000,000,000 | |||