CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Millions, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock, at Cost	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2013	$ 19,196	$ 6	$ 18,603	$ 1,235	$ 0	$ (648)
Beginning balance (in shares) at Dec. 31, 2013		560,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividend to RBS	(25)			(25)
Net income	166			166
Other comprehensive income (loss)	105					105
Total comprehensive income	271			166		105
Ending balance at Mar. 31, 2014	19,442	6	18,603	1,376	0	(543)
Ending balance (in shares) at Mar. 31, 2014		560,000,000
Beginning balance at Dec. 31, 2014	19,268	6	18,676	1,294	(336)	(372)
Beginning balance (in shares) at Dec. 31, 2014		546,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividend to common stockholders	(16)			(16)
Dividend to RBS	(39)			(39)
Common shares repurchased for share-based compensation (in shares)	804,507	1,000,000
Share-based compensation plans	8		29		(21)
Employee stock purchase plan shares purchased	2		2
Net income	209			209
Other comprehensive income (loss)	132					132
Total comprehensive income	341			209		132
Ending balance at Mar. 31, 2015	$ 19,564	$ 6	$ 18,707	$ 1,448	$ (357)	$ (240)
Ending balance (in shares) at Mar. 31, 2015		547,000,000