Stockholders' Equity Table Of Changes In AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	$ (339)
Other comprehensive income (loss)	6	$ 93
Total, Ending Balance	(334)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	(339)
Other comprehensive income (loss) before reclassifications	2
Amounts reclassified from accumulated other comprehensive income (loss)	3
Other comprehensive income (loss)	5
Total, Ending Balance	(334)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total, Beginning Balance	0
Other comprehensive income (loss) before reclassifications	2
Amounts reclassified from accumulated other comprehensive income (loss)	0
Other comprehensive income (loss)	2
Total, Ending Balance	2
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)
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)	3
Other comprehensive income (loss)	3
Total, Ending Balance	(334)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)	$ 3