Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		96 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2025
Income Tax Contingency [Line Items]
Effective income tax rate	20.70%	24.70%
Noncash Pension Settlement Charge - tax effect		$ 8
Minimum | Scenario, Forecast [Member]
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount			$ 1
Maximum | Scenario, Forecast [Member]
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount			$ 3