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, 2017	$ 29,695	$ 3,910	$ 3,053	$ 7,893	$ 16,259	$ (1,467)	$ 47
Beginning balance (in shares) at Dec. 31, 2017		782,006
Add (Deduct):
Net income	791				788		3
OCI	(178)					(178)
Stock transactions:
Issued in connection with equity awards, net	(13)	$ 18		(31)
Issued in connection with equity awards, net (in shares)		3,599
Repurchase of common stock (in shares)		(5,853)
Repurchase of common stock	(320)	$ (29)		(291)
Cash dividends declared on common stock	(292)				(292)
Cash dividends declared on preferred stock	(43)				(43)
Equity-based compensation expense	31			31
Other, net	(9)			(9)
Ending balance at Mar. 31, 2018	29,662	$ 3,899	3,053	7,593	16,712	(1,645)	50
Ending balance (in shares) at Mar. 31, 2018		779,752
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	763,326
Add (Deduct):
Net income	$ 798				792		6
OCI	294					294
Stock transactions:
Issued in connection with equity awards, net	(28)	$ 13		(41)
Issued in connection with equity awards, net (in shares)		2,594
Cash dividends declared on common stock	(309)				(309)
Cash dividends declared on preferred stock	(43)				(43)
Equity-based compensation expense	32			32
Other, net	(39)			3	(40)		(2)
Ending balance at Mar. 31, 2019	$ 30,883	$ 3,830	$ 3,053	$ 6,843	$ 18,518	$ (1,421)	$ 60
Ending balance (in shares) at Mar. 31, 2019	765,920	765,920