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
Beginning balance at Dec. 31, 2015		$ 26,068	$ 4,105	$ 92,500	$ 146,420	$ 192	$ (21)	$ (21,691)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		0
Redemption		0
Shares issued and commitments to issue common stock for employee share-based compensation awards, and related tax effects				(334)
Other				(539)
Net income	$ 24,733				24,733
Dividends declared:
Preferred stock					(1,647)
Common stock ($2.72, $2.12 and $1.88 per share for 2018, 2017 and 2016, respectively)					(6,912)
Other comprehensive income/(loss), after-tax	(1,521)					(1,521)
Repurchase			(9,082)					(9,082)
Reissuance								1,919
Ending balance at Dec. 31, 2016	254,190	26,068	4,105	91,627	162,440	(1,175)	(21)	(28,854)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		1,258
Redemption		(1,258)
Shares issued and commitments to issue common stock for employee share-based compensation awards, and related tax effects				(734)
Other				(314)
Net income	24,441				24,441
Dividends declared:
Preferred stock					(1,663)
Common stock ($2.72, $2.12 and $1.88 per share for 2018, 2017 and 2016, respectively)					(7,542)
Other comprehensive income/(loss), after-tax	1,056					1,056
Repurchase			(15,410)					(15,410)
Reissuance								1,669
Ending balance at Dec. 31, 2017	255,693	26,068	4,105	90,579	177,676	(119)	(21)	(42,595)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		1,696
Redemption		(1,696)
Shares issued and commitments to issue common stock for employee share-based compensation awards, and related tax effects				(738)
Other				(679)
Net income	32,474				32,474
Dividends declared:
Preferred stock					(1,551)
Common stock ($2.72, $2.12 and $1.88 per share for 2018, 2017 and 2016, respectively)					(9,214)
Other comprehensive income/(loss), after-tax	(1,476)					(1,476)
Repurchase			(19,983)					(19,983)
Reissuance								2,084
Ending balance at Dec. 31, 2018	$ 256,515	$ 26,068	$ 4,105	$ 89,162	$ 199,202	$ (1,507)	$ (21)	$ (60,494)