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
Statement of Comprehensive Income [Abstract]
Changes in unrealized gains (losses) - taxes (benefits)	$ 16	$ 0	$ 65	$ (16)
Reclassification adjustment for net losses (gains) realized in net income - benefits (taxes)	(5)	0	(11)	(4)
Changes in market value of derivatives - taxes (benefits)	3	(1)	3	2
Reclassification adjustment for net losses (gains) realized in net income - benefits (taxes)	$ 0	$ 0	$ 0	$ (2)