CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 87	$ 179	$ 251	$ 283
Net change in unrealized gains (losses), net of tax:
Investment securities	(213)	175	(241)	305
Other-than-temporarily impaired debt securities held-to-maturity	0	2	0	3
Derivatives designated as cash flow hedges	31	(15)	12	(35)
Pension and post-retirement benefit plans	0	0	1	0
Total other comprehensive income (loss)	(182)	162	(228)	273
Comprehensive income (loss)	$ (95)	$ 341	$ 23	$ 556