CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Unrealized gain on derivative instruments, net of income tax expense of $0, $1, $3 and $1	$ 0	$ 1	$ 3	$ 1
Reclassification of (gain) loss on settled derivative instruments, net of income tax expense (benefit) of $12 million, ($10) million and ($139) million	2	1	12	8
Unrealized loss on investments, net of income tax benefit of $0, ($1), $0 and ($4)	0	(1)	0	(4)
Reclassification of (gain) loss on investment, net of income tax expense (benefit) of $3 million, $0 and $0	$ 0	$ (1)	$ (3)	$ 3