CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS) (UNAUDITED) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 220	$ (258)	$ 446	$ (413)
Net change in unrealized gains (losses), net of tax, on:
Derivatives designated as cash flow hedges	38	(5)	206	50
Securities available-for-sale, not other-than temporarily impaired	0	15	(115)	6
Other-than-temporarily impaired debt securities available-for-sale	0	1	(1)	1
Pension and postretirement benefit plan adjustments, net of tax	1	1	1	1
Foreign currency translation adjustments, net of tax	9	(5)	(11)	0
Other comprehensive income, net of tax	48	7	80	58
Total comprehensive income (loss)	$ 268	$ (251)	$ 526	$ (355)