Stockholders' Equity Table Of Changes In AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			$ (339)
Other comprehensive income (loss)	$ (3)	$ 76	6	$ 180
Total, Ending Balance	(331)		(331)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(339)
Other comprehensive income (loss) before reclassifications			(3)
Amounts reclassified from accumulated other comprehensive income (loss)			11
Other comprehensive income (loss)			8
Total, Ending Balance	(331)		(331)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			0
Other comprehensive income (loss) before reclassifications			(3)
Amounts reclassified from accumulated other comprehensive income (loss)			0
Other comprehensive income (loss)			(3)
Total, Ending Balance	(3)		(3)
Foreign Currency Translation
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)
Pension and Other Post Retirement Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance			(337)
Other comprehensive income (loss) before reclassifications			0
Amounts reclassified from accumulated other comprehensive income (loss)			11
Other comprehensive income (loss)			11
Total, Ending Balance	$ (326)		(326)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)			$ 11