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	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		8,905
Shares issued and commitments to issue common stock for employee stock-based compensation awards, and related tax effects				(719)
Other				(49)
Net income	$ 16,814				16,814
Dividends declared:
Preferred stock					(799)
Common stock ($1.28 and $1.18 per share)					(4,554)
Other comprehensive income	2,067					2,067
Purchase of treasury stock								(3,250)
Reissuance from treasury stock								1,667
Ending balance at Sep. 30, 2014	230,939	20,063	4,105	93,060	126,896	3,266	(21)	(16,430)
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		6,005
Shares issued and commitments to issue common stock for employee stock-based compensation awards, and related tax effects				(635)
Other				(319)
Net income	19,008				19,008
Dividends declared:
Preferred stock					(1,097)
Common stock ($1.28 and $1.18 per share)					(4,838)
Other comprehensive income	(1,438)					(1,438)
Purchase of treasury stock								(4,397)
Reissuance from treasury stock								1,712
Ending balance at Sep. 30, 2015	$ 245,728	$ 26,068	$ 4,105	$ 92,316	$ 143,050	$ 751	$ (21)	$ (20,541)