Consolidated Statements of Changes in Stockholders' Equity (USD $) In Millions, unless otherwise specified	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, 2011		$ 7,800	$ 4,105	$ 95,602	$ 88,315	$ 944	$ (38)	$ (13,155)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of preferred stock		1,258
Redemption of preferred stock		0
Shares issued and commitments to issue common stock for employee stock-based compensation awards, and related tax effects				(736)
Other				(262)
Net income	21,284				21,284
Dividends declared:
Preferred stock					(647)
Common stock ($1.58, $1.44 and $1.20 per share for 2014, 2013 and 2012, respectively)					(4,729)
Other comprehensive income/(loss)	3,158					3,158
Reissuance from RSU Trust							17
Purchase of treasury stock			(1,329)					(1,415)
Reissuance from treasury stock								2,574
Share repurchases related to employee stock-based compensation awards								(6)
Ending balance at Dec. 31, 2012	204,069	9,058	4,105	94,604	104,223	4,102	(21)	(12,002)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of preferred stock		3,900
Redemption of preferred stock		(1,800)
Shares issued and commitments to issue common stock for employee stock-based compensation awards, and related tax effects				(752)
Other				(24)
Net income	17,923				17,923
Dividends declared:
Preferred stock					(805)
Common stock ($1.58, $1.44 and $1.20 per share for 2014, 2013 and 2012, respectively)					(5,585)
Other comprehensive income/(loss)	(2,903)					(2,903)
Reissuance from RSU Trust							0
Purchase of treasury stock			(4,789)					(4,789)
Reissuance from treasury stock								1,944
Share repurchases related to employee stock-based compensation awards								0
Ending balance at Dec. 31, 2013	211,178	11,158	4,105	93,828	115,756	1,199	(21)	(14,847)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of preferred stock		8,905
Redemption of preferred stock		0
Shares issued and commitments to issue common stock for employee stock-based compensation awards, and related tax effects				(508)
Other				(50)
Net income	21,762				21,762
Dividends declared:
Preferred stock					(1,125)
Common stock ($1.58, $1.44 and $1.20 per share for 2014, 2013 and 2012, respectively)					(6,078)
Other comprehensive income/(loss)	990					990
Reissuance from RSU Trust							0
Purchase of treasury stock			(4,834)					(4,760)
Reissuance from treasury stock								1,751
Share repurchases related to employee stock-based compensation awards								0
Ending balance at Dec. 31, 2014	$ 232,065	$ 20,063	$ 4,105	$ 93,270	$ 130,315	$ 2,189	$ (21)	$ (17,856)