Stockholders' Equity Table Of Changes In AOCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			$ (270)
Other comprehensive income (loss)	$ 2	$ (3)	5	$ 3
Total, Ending Balance	(265)		(265)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(270)
Amounts reclassified from accumulated other comprehensive income (loss)			5
Other comprehensive income (loss)	2	$ 1	5	$ 6
Total, Ending Balance	(265)		(265)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(2)
Amounts reclassified from accumulated other comprehensive income (loss)			0
Total, Ending Balance	(2)		(2)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(1)
Amounts reclassified from accumulated other comprehensive income (loss)			0
Total, Ending Balance	(1)		(1)
Pension and Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(267)
Amounts reclassified from accumulated other comprehensive income (loss)			5
Total, Ending Balance	$ (262)		(262)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)			$ 5