Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Preferred stock	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income/(loss)	Shares held in RSU Trust, at cost	Treasury stock, at cost
Beginning balance at Dec. 31, 2013		$ 11,158	$ 4,105	$ 93,828	$ 115,756	$ 1,199	$ (21)	$ (14,847)
Cumulative effect of change in accounting principle at Dec. 31, 2013					(321)
Balance at beginning of year, adjusted at Dec. 31, 2013					115,435
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of preferred stock		7,305
Shares issued and commitments to issue common stock for employee stock-based compensation awards, and related tax effects				(901)
Other				(48)
Net income	$ 11,249				11,249
Dividends declared:
Preferred stock					(495)
Common stock ($0.84 and $0.78 per share)					(3,023)
Other comprehensive income	2,239					2,239
Purchase of treasury stock								(1,761)
Reissuance from treasury stock								1,561
Ending balance at Jun. 30, 2014	226,983	18,463	4,105	92,879	123,166	3,438	(21)	(15,047)
Beginning balance at Dec. 31, 2014		20,063	4,105	93,270	129,977	2,189	(21)	(17,856)
Cumulative effect of change in accounting principle at Dec. 31, 2014					0
Balance at beginning of year, adjusted at Dec. 31, 2014					129,977
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of preferred stock		4,855
Shares issued and commitments to issue common stock for employee stock-based compensation awards, and related tax effects				(788)
Other				(278)
Net income	12,204				12,204
Dividends declared:
Preferred stock					(704)
Common stock ($0.84 and $0.78 per share)					(3,183)
Other comprehensive income	(1,087)					(1,087)
Purchase of treasury stock								(3,149)
Reissuance from treasury stock								1,608
Ending balance at Jun. 30, 2015	$ 241,205	$ 24,918	$ 4,015	$ 92,204	$ 138,294	$ 1,102	$ (21)	$ (19,397)