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, 2017		$ 26,068	$ 4,105	$ 90,579	$ 177,676	$ (119)	$ (21)	$ (42,595)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		0
Redemption		0
Shares issued and commitments to issue common stock for employee shared-based compensation awards, and related tax effects				(1,076)
Other				(111)
Net income	$ 17,028				17,028
Dividends declared:
Preferred stock					(788)
Common stock					(3,852)
Other comprehensive income/(loss), after-tax	(1,107)					(1,107)
Repurchase								(9,639)
Reissuance								1,405
Ending balance at Jun. 30, 2018	257,458	26,068	4,105	89,392	189,881	(1,138)	(21)	(50,829)
Beginning balance at Mar. 31, 2018		26,068	4,105	89,211	183,855	(1,063)	(21)	(45,954)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		0
Redemption		0
Shares issued and commitments to issue common stock for employee shared-based compensation awards, and related tax effects				231
Other				(50)
Net income	8,316				8,316
Dividends declared:
Preferred stock					(379)
Common stock					(1,911)
Other comprehensive income/(loss), after-tax	(75)					(75)
Repurchase								(4,968)
Reissuance								93
Ending balance at Jun. 30, 2018	257,458	26,068	4,105	89,392	189,881	(1,138)	(21)	(50,829)
Beginning balance at Dec. 31, 2018	256,515	26,068	4,105	89,162	199,202	(1,507)	(21)	(60,494)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		1,850
Redemption		(925)
Shares issued and commitments to issue common stock for employee shared-based compensation awards, and related tax effects				(760)
Other				(43)
Net income	18,831				18,831
Dividends declared:
Preferred stock					(778)
Common stock					(5,224)
Other comprehensive income/(loss), after-tax	2,621					2,621
Repurchase								(10,301)
Reissuance								1,367
Ending balance at Jun. 30, 2019	263,215	26,993	4,105	88,359	212,093	1,114	(21)	(69,428)
Beginning balance at Mar. 31, 2019		26,993	4,105	88,170	205,437	(558)	(21)	(64,289)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		0
Redemption		0
Shares issued and commitments to issue common stock for employee shared-based compensation awards, and related tax effects				189
Other				0
Net income	9,652				9,652
Dividends declared:
Preferred stock					(404)
Common stock					(2,592)
Other comprehensive income/(loss), after-tax	1,672					1,672
Repurchase								(5,210)
Reissuance								71
Ending balance at Jun. 30, 2019	$ 263,215	$ 26,993	$ 4,105	$ 88,359	$ 212,093	$ 1,114	$ (21)	$ (69,428)