Consolidated Statements of Changes in Shareholders' Equity (USD $) In Millions, except Share data in Thousands, unless otherwise specified	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	AOCI [Member]	Noncontrolling Interests [Member]
Beginning balance, Value at Dec. 31, 2011	$ 17,480	$ 0	$ 3,486	$ 5,873	$ 8,772	$ (713)	$ 62
Beginning balance, Shares at Dec. 31, 2011			697,143
Add (Deduct):
Net income	2,028				1,979		49
Net change in AOCI	154					154
Stock transactions:
In purchase acquisitions, Shares			28
In purchase acquisitions, Values	1			1
In connection with equity awards, Shares			3,147
In connection with equity awards, Values	33		16	17
Shares repurchased in connection with equity awards, Shares			(590)
Shares repurchased in connection with equity awards, Value	(18)		(3)	(15)
In connection with preferred stock offerings	2,116	2,116
Cash dividends declared on common stock	(559)				(559)
Cash dividends declared on preferred stock	(63)				(63)
Equity-based compensation expense	97			97
Other, net	(46)						(46)
Ending balance, Value at Dec. 31, 2012	21,223	2,116	3,499	5,973	10,129	(559)	65
Ending balance, Shares at Dec. 31, 2012			699,728
Add (Deduct):
Net income	1,729				1,679		50
Net change in AOCI	(34)					(34)
Stock transactions:
In connection with equity awards, Shares			6,257
In connection with equity awards, Values	105		31	74
Shares repurchased in connection with equity awards, Shares			(879)
Shares repurchased in connection with equity awards, Value	(27)		(4)	(23)
In connection with dividend reinvestment plan, Shares			656
In connection with dividend reinvestment plan, Value	22		3	19
In connection with 401(k) plan, Shares			858
In connection with 401(k) plan, Value	29		4	25
In connection with preferred stock offerings	487	487
Cash dividends declared on common stock	(647)				(647)
Cash dividends declared on preferred stock	(117)				(117)
Equity-based compensation expense	96			96
Other, net	(57)			8			(65)
Ending balance, Value at Dec. 31, 2013	22,809	2,603	3,533	6,172	11,044	(593)	50
Ending balance, Shares at Dec. 31, 2013			706,620
Add (Deduct):
Net income	2,226				2,151		75
Net change in AOCI	(158)					(158)
Stock transactions:
In connection with equity awards, Shares			15,321
In connection with equity awards, Values	309		76	233
Shares repurchased in connection with equity awards, Shares			(2,287)
Shares repurchased in connection with equity awards, Value	(85)		(11)	(74)
Excess tax benefits in connection with equity awards	(49)			(49)
In connection with dividend reinvestment plan, Shares			391
In connection with dividend reinvestment plan, Value	15		2	13
In connection with 401(k) plan, Shares			653
In connection with 401(k) plan, Value	25		3	22
In connection with preferred stock offerings	0
Cash dividends declared on common stock	(681)				(681)
Cash dividends declared on preferred stock	(148)				(148)
Equity-based compensation expense	102			102
Other, net	(37)						(37)
Ending balance, Value at Dec. 31, 2014	$ 24,426	$ 2,603	$ 3,603	$ 6,517	$ 12,366	$ (751)	$ 88
Ending balance, Shares at Dec. 31, 2014			720,698