Stockholders' Equity Table Of Changes In AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			$ (199)
Other comprehensive income (loss)	$ 16	$ (1)	39	$ 4
Total, Ending Balance	(160)		(160)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(199)
Other comprehensive income (loss) before reclassifications			20
Amounts reclassified from accumulated other comprehensive income (loss)			19
Other comprehensive income (loss)	16	$ (1)	39	$ 4
Total, Ending Balance	(160)		(160)
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)		(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)		(1)
Pension and Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(196)
Other comprehensive income (loss) before reclassifications			20
Amounts reclassified from accumulated other comprehensive income (loss)			19
Other comprehensive income (loss)			39
Total, Ending Balance	$ (157)		$ (157)