CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS) (UNAUDITED) (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]
Net income	$ 1	$ 4	$ 284	$ 367
Net change in unrealized gains (losses), net of tax:
Investment securities	(87)	(50)	218	(785)
Other-than-temporarily impaired debt securities held-to-maturity	6	2	9	2
Derivatives designated as cash flow hedges	(5)	21	(40)	95
Pension and post-retirement benefit plan	0	1	0	1
Total other comprehensive income (loss)	(86)	(26)	187	(687)
Comprehensive income (loss)	$ (85)	$ (22)	$ 471	$ (320)