Supplemental Equity and Comprehensive Income Information - Stock Narrative (Details) - $ / shares |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|---|---|---|---|---|
| Supplemental Equity and Comprehensive Income Information | ||||
| Common stock, par value per share (in dollars per share) | $ 0.01 | $ 0.01 | $ 0.01 | |
| Common stock, shares authorized (in shares) | 3,000,000,000 | 3,000,000,000 | 3,000,000,000 | |
| Common stock, shares issued (in shares) | 944,033,056 | 944,033,056 | 944,033,056 | |
| Treasury stock (in shares) | 347,306,778 | 334,702,932 | 308,898,462 | 280,736,817 |
| Preferred stock, shares authorized | 10,000,000 | 10,000,000 | 10,000,000 |