CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (404)	$ (37)	$ (612)	$ (258)
Net change in unrealized gains (losses), net of tax, on:
Derivatives designated as cash flow hedges	0	8	15	28
Pension and postretirement benefit plan adjustments	0	0	(3)	0
Other comprehensive income, net of tax	0	8	12	28
Total comprehensive income (loss)	$ (404)	$ (29)	$ (600)	$ (230)