Income Taxes (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Income Tax Disclosure [Abstract] | ||||
| Provision for income taxes | $ 30 | $ 24 | $ 73 | $ 70 |
| Effective tax provision rate (as a percent) | 34.30% | 34.40% | 33.80% | 36.00% |
| Unrecognized tax benefits, recognition period (in months) | 12 months | |||