Stockholders' Equity Table Of Changes In AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			$ (270)
Other comprehensive income (loss)	$ (1)	$ 6	4	$ 9
Total, Ending Balance	(266)		(266)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(270)
Other comprehensive income (loss) before reclassifications			(5)
Amounts reclassified from accumulated other comprehensive income (loss)			9
Other comprehensive income (loss)	(1)	$ 5	4	$ 11
Total, Ending Balance	(266)		(266)
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			(267)
Other comprehensive income (loss) before reclassifications			(5)
Amounts reclassified from accumulated other comprehensive income (loss)			9
Other comprehensive income (loss)			4
Total, Ending Balance	$ (263)		(263)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)			$ 9