Stockholders' Equity Table Of Changes In AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	$ (199)
Other comprehensive income (loss)	(6)	$ 3
Total, Ending Balance	(205)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	(199)
Other comprehensive income (loss) before reclassifications	(14)
Amounts reclassified from accumulated other comprehensive income (loss)	8
Other comprehensive income (loss)	(6)	$ 3
Total, Ending Balance	(205)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	(2)
Other comprehensive income (loss) before reclassifications	0
Amounts reclassified from accumulated other comprehensive income (loss)	0
Other comprehensive income (loss)	0
Total, Ending Balance	(2)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	(1)
Other comprehensive income (loss) before reclassifications	0
Amounts reclassified from accumulated other comprehensive income (loss)	0
Other comprehensive income (loss)	0
Total, Ending Balance	(1)
Pension and Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	(196)
Other comprehensive income (loss) before reclassifications	(14)
Amounts reclassified from accumulated other comprehensive income (loss)	8
Other comprehensive income (loss)	(6)
Total, Ending Balance	$ (202)