Income Taxes (Details) - USD ($) |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2017 |
Jun. 30, 2018 |
Jun. 30, 2017 |
|
| Income Tax Disclosure [Abstract] | ||||
| Effective tax rate | 24.70% | 39.10% | 24.10% | 37.90% |
| Cash paid for income taxes | $ 30,000,000 | $ 170,000,000 | ||
| Accrued liability for penalties | $ 500,000 | 500,000 | ||
| Accrued liability for interest related to uncertain tax positions and penalties | 11,300,000 | 11,300,000 | ||
| Unrecognized tax benefits settlements with taxing authorities, minimum | 0 | |||
| Unrecognized tax benefits settlements with taxing authorities, maximum | 10,000,000 | |||
| Valuation allowance, state loss carryforwards | $ 72,000,000 | $ 72,000,000 | ||