Consolidated Statements of Changes in Stockholders' Equity - 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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle					$ 0	$ 0
Beginning balance at Dec. 31, 2013		$ 11,158	$ 4,105	$ 93,828	115,435	1,199	$ (21)	$ (14,847)
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				(508)
Other				(50)
Net income	$ 21,745				21,745
Dividends declared:
Preferred stock					(1,125)
Common stock ($1.88, $1.72 and $1.58 per share for 2016, 2015 and 2014, respectively)					(6,078)
Other comprehensive income/(loss)	990					990
Purchase of treasury stock			(4,760)					(4,760)
Reissuance from treasury stock								1,751
Ending balance at Dec. 31, 2014	231,727	20,063	4,105	93,270	129,977	2,189	(21)	(17,856)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle					0	0
Issuance of preferred stock		6,005
Shares issued and commitments to issue common stock for employee stock-based compensation awards, and related tax effects				(436)
Other				(334)
Net income	24,442				24,442
Dividends declared:
Preferred stock					(1,515)
Common stock ($1.88, $1.72 and $1.58 per share for 2016, 2015 and 2014, respectively)					(6,484)
Other comprehensive income/(loss)	(1,997)					(1,997)
Purchase of treasury stock			(5,616)					(5,616)
Reissuance from treasury stock								1,781
Ending balance at Dec. 31, 2015	247,573	26,068	4,105	92,500	146,420	192	(21)	(21,691)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle					(154)	154
Issuance of preferred stock		0
Shares issued and commitments to issue common stock for employee stock-based compensation awards, and related tax effects				(334)
Other				(539)
Net income	24,733				24,733
Dividends declared:
Preferred stock					(1,647)
Common stock ($1.88, $1.72 and $1.58 per share for 2016, 2015 and 2014, respectively)					(6,912)
Other comprehensive income/(loss)	(1,521)					(1,521)
Purchase of treasury stock			(9,082)					(9,082)
Reissuance from treasury stock								1,919
Ending balance at Dec. 31, 2016	$ 254,190	$ 26,068	$ 4,105	$ 91,627	$ 162,440	$ (1,175)	$ (21)	$ (28,854)