Consolidated Statements of Changes in Shareholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Preferred Stock	Additional Paid-In Capital	Retained Earnings	AOCI	Noncontrolling Interests
Beginning balance at Dec. 31, 2018	$ 30,178	$ 3,817	$ 3,053	$ 6,849	$ 18,118	$ (1,715)	$ 56
Beginning balance (in shares) at Dec. 31, 2018		763,326
Add (Deduct):
Net income	3,237				3,224		13
OCI	871					871
Stock transactions:
Issued in business combination	33,546	$ 2,875	2,045	28,626
Issued in business combinations (in shares)		575,067
Issued in connection with equity awards, net	(15)	$ 19		(34)
Issued in connection with equity awards, net (in shares)		3,773
Issued in connection with preferred stock offering	1,683		1,683
Redemption of preferred stock	(1,725)		(1,679)		(46)
Cash dividends declared on common stock	(1,309)				(1,309)
Cash dividends declared on preferred stock	(150)				(150)
Equity-based compensation expense	165			165
Other, net	77			3	(31)		105
Ending balance at Dec. 31, 2019	66,558	$ 6,711	5,102	35,609	19,806	(844)	174
Ending balance (in shares) at Dec. 31, 2019		1,342,166
Add (Deduct):
Net income	4,492				4,482		10
OCI	1,560					1,560
Stock transactions:
Issued in business combination	0
Issued in connection with equity awards, net	(87)	$ 34		(119)	(2)
Issued in connection with equity awards, net (in shares)		6,795
Issued in connection with preferred stock offering	3,449		3,449
Redemption of preferred stock	(500)		(503)		3
Cash dividends declared on common stock	(2,424)				(2,424)
Cash dividends declared on preferred stock	(301)				(301)
Equity-based compensation expense	353			353
Cumulative effect adjustment for new accounting standards	(2,109)				(2,109)
Other, net	(79)						(79)
Ending balance at Dec. 31, 2020	$ 70,912	$ 6,745	8,048	35,843	19,455	716	105
Ending balance (in shares) at Dec. 31, 2020	1,348,961	1,348,961
Add (Deduct):
Net income	$ 6,437				6,440		(3)
OCI	(2,320)					(2,320)
Stock transactions:
Issued in business combination	0
Issued in connection with equity awards, net	(93)	$ 32		(120)	(5)
Issued in connection with equity awards, net (in shares)		6,466
Repurchase of common stock (in shares)		(27,609)
Repurchase of common stock	(1,616)	$ (138)		(1,478)
Redemption of preferred stock	(1,415)		(1,375)		(40)
Cash dividends declared on common stock	(2,485)				(2,485)
Cash dividends declared on preferred stock	(367)				(367)
Equity-based compensation expense	320			320
Other, net	(102)						(102)
Ending balance at Dec. 31, 2021	$ 69,271	$ 6,639	$ 6,673	$ 34,565	$ 22,998	$ (1,604)	$ 0
Ending balance (in shares) at Dec. 31, 2021	1,327,818	1,327,818