CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Unrealized gains (losses) on derivative instruments, net of income tax expense (benefit) of ($1) and $1	$ (1)	$ 1
Reclassification of (gain) loss on settled derivative instruments, net of income tax expense (benefit) of $12 million, ($10) million and ($139) million	7	7
Reclassification of (gain) loss on investment, net of income tax expense (benefit) of $3 million, $0 and $0	$ 0	$ (3)