Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net income	$ 159	$ 139	$ 427	$ 432
Other comprehensive income (loss):
Fair market value adjustment on cash flow hedges, net of income taxes of $1 million, $1 million and $8 million		(2)	(2)	(12)
Reclassification adjustment for net realized losses on cash flow hedges included in interest expense, net of income taxes of $1 million, $7 million, $4 million and $16 million	2	10	7	24
Foreign currency translation	2	4	(8)	5
Total other comprehensive income (loss)	4	12	(3)	17
Comprehensive income	$ 163	$ 151	$ 424	$ 449