Stockholders' Equity Table Of Changes In AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	$ (270)
Other comprehensive income (loss)	3	$ 6
Total, Ending Balance	(267)
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)	3
Other comprehensive income (loss)	3	$ 5
Total, Ending Balance	(267)
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)
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)
Pension and Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	(267)
Amounts reclassified from accumulated other comprehensive income (loss)	3
Total, Ending Balance	(264)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)	$ 3