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				(1,307)
Other				(61)
Net income	$ 8,712				8,712
Dividends declared:
Preferred stock					(409)
Common stock ($0.80 and $0.56 per share)					(1,941)
Other comprehensive income/(loss), after-tax	(1,032)					(1,032)
Repurchase								(4,671)
Reissuance								1,312
Ending balance at Mar. 31, 2018	256,201	26,068	4,105	89,211	183,855	(1,063)	(21)	(45,954)
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				(949)
Other				(43)
Net income	9,179				9,179
Dividends declared:
Preferred stock					(374)
Common stock ($0.80 and $0.56 per share)					(2,632)
Other comprehensive income/(loss), after-tax	949					949
Repurchase								(5,091)
Reissuance								1,296
Ending balance at Mar. 31, 2019	$ 259,837	$ 26,993	$ 4,105	$ 88,170	$ 205,437	$ (558)	$ (21)	$ (64,289)