Income Taxes Level 4 (Details) - Presentation of the Net Deferred Tax Liability - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Long-term deferred income taxes	$ 0	$ (8)
Liabilities [Abstract]
Long-term deferred income taxes	(15)	(11)
Net deferred tax liability	(15)	(3)
net operating loss carryforward reduction	26
Valuation allowance	547	522	$ 651	$ 611
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	1,048
Valuation allowance on state net operating loss carryforwards	77
Operating Loss Carryforwards, Valuation Allowance	115
Unrepatriated earnings of foreign subsidiaries	$ 10	$ 9