CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income tax expense (benefit) of $0, $20 and $1 on unrealized gains (losses) on derivative instruments	$ (14)	$ 12	$ 0
Income tax expense (benefit) of $0, and $4 on reclassification of (gains) losses on settled derivative instruments	18	15	14
Income tax expense (benefit) of $0, $0 and ($3) on reclassification of (gains) losses on investment	$ 0	$ 0	$ (3)