Consolidated Statement of Changes In Shareholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	PREFERRED STOCK	COMMON STOCK	Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	TREASURY STOCK
Beginning balance at Dec. 31, 2013	$ 20,378	$ 491	$ 504	$ 9,776	$ 13,395	$ (95)	$ (3,693)
Beginning balance (shares) at Dec. 31, 2013			503,883				69,754
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	985				985
Other comprehensive income (loss)	584					584
Preferred stock issued	742	742
Cash dividends declared:
Common stock dividends	(240)				(240)
Preferred stock cash dividend	(25)				(25)
Common stock acquired	(830)						$ (830)
Common stock acquired (shares)							12,380
Common stock awards and options exercised, including related taxes	107			(11)			$ 118
Common stock awards and options exercised, including related taxes (shares)			2				3,221
Other	(1)				(1)
Other (shares)							3
Ending balance (shares) at Jun. 30, 2014			503,881				78,910
Ending balance at Jun. 30, 2014	21,700	1,233	$ 504	9,765	14,114	489	$ (4,405)
Beginning balance at Dec. 31, 2014	21,473	1,961	$ 504	9,791	14,882	(507)	$ (5,158)
Beginning balance (shares) at Dec. 31, 2014			503,880				88,685
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	831
Other comprehensive income (loss)	(504)					(504)
Preferred stock issued	742	742
Cash dividends declared:
Common stock dividends	(262)				(262)
Preferred stock cash dividend	(60)				(60)
Common stock acquired	(820)						$ (820)
Common stock acquired (shares)							10,719
Common stock awards and options exercised, including related taxes	107			(41)			$ 148
Common stock awards and options exercised, including related taxes (shares)							3,274
Other	(7)			(6)	(1)
Other (shares)							4
Ending balance (shares) at Jun. 30, 2015			503,880				96,126
Ending balance at Jun. 30, 2015	$ 21,500	$ 2,703	$ 504	$ 9,744	$ 15,390	$ (1,011)	$ (5,830)