Income Taxes - Additional Information (Details) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
Mar. 31, 2019 |
Mar. 31, 2018 |
Mar. 31, 2017 |
Dec. 31, 2017 |
|
| US federal statutory income tax rate | 21.00% | 35.00% | 35.00% | |
| Income tax expense | $ 48 | $ 30 | ||
| Effective income tax rate | 31.00% | 29.00% | ||
| Expense related to future taxes on repatriations from operations | $ 2 | $ 2 | ||
| Withholding tax related to actual transfer of funds | $ 3 | $ 2 | ||
| Maximum [Member] | Scenario, Forecast [Member] | ||||
| Possible release of valuation allowance | $ 8 | |||