Consolidated Statement of Changes in Shareholders' Equity (Unaudited) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Convertible preferred stock - savings plan
Convertible preferred stock - savings plan, balance, beginning of year			$ 68	$ 79
Convertible preferred stock - savings plan, redemptions			(5)	(9)
Convertible preferred stock - savings plan, conversion to common stock			(63)
Convertible preferred stock - savings plan, balance, end of period		70		70
Common stock
Common stock, balance, beginning of year			20,162	19,593
Common stock, employee share-based compensation			286	276
Common stock, common shares issued - conversion of preferred stock			93
Common stock, compensation amortization under share-based plans and other changes			123	111
Common stock, balance, end of period	20,664	19,980	20,664	19,980
Retained earnings
Retained earnings, balance, beginning of year			18,847	16,315
Net income	333	1,005	808	2,322
Dividends			(503)	(515)
Premium on preferred stock converted to common stock			(30)
Retained earnings, other			5	(4)
Retained earnings, balance, end of period	19,127	18,118	19,127	18,118
Accumulated other changes in equity from nonowner sources, net of tax
Accumulated other changes in equity from nonowner sources, balance, beginning of year			1,255	1,219
Change in net unrealized gain on investment securities having no credit losses recognized in the consolidated statement of income	389	585	758	1,061
Change in net unrealized gain on investment securities having credit losses recognized in the consolidated statement of income	(6)	24	6	68
Net change in unrealized foreign currency translation and other changes	(62)	73	13	24
Accumulated other changes in equity from nonowner sources, balance, end of period	2,032	2,372	2,032	2,372
Treasury stock (at cost)
Treasury stock (at cost), balance, beginning of year			(14,857)	(9,791)
Treasury stock (at cost), treasury shares acquired - share repurchase authorization			(1,712)	(3,400)
Treasury stock (at cost), net shares acquired related to employee share-based compensation plans			(82)	(54)
Treasury stock (at cost), balance, end of period	(16,651)	(13,245)	(16,651)	(13,245)
Total common shareholders' equity	25,172	27,225	25,172	27,225
Total shareholders' equity	25,172	27,295	25,172	27,295
Common shares outstanding
Common shares outstanding, balance, beginning of year			434.6	520.3
Common shares outstanding, treasury shares acquired - share repurchase authorization			(30.1)	(66.8)
Common shares outstanding, common shares issued - conversion of preferred stock			1.5
Common shares outstanding, net shares issued under employee share-based compensation plans			6.8	7.0
Common shares outstanding, balance, end of period	412.8	460.5	412.8	460.5
Summary of changes in equity from nonowner sources
Net income	333	1,005	808	2,322
Other changes in equity from nonowner sources, net of tax			777	1,153
Total changes in equity from nonowner sources	$ 654	$ 1,687	$ 1,585	$ 3,475