Stockholders' Equity (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Number of Common shares Issued [Member]	Sep. 30, 2010 Number of Common shares Issued [Member]	Sep. 30, 2011 Number of Common shares Treasury [Member]	Sep. 30, 2010 Number of Common shares Treasury [Member]	Sep. 30, 2011 Common Stockholders' Equity [Member]	Sep. 30, 2010 Common Stockholders' Equity [Member]	Sep. 30, 2011 Preferred and Preference Stock of Subsidiaries [Member]	Dec. 31, 2010 Preferred and Preference Stock of Subsidiaries [Member]	Sep. 30, 2010 Preferred and Preference Stock of Subsidiaries [Member]	Dec. 31, 2009 Preferred and Preference Stock of Subsidiaries [Member]
Changes in Stockholders' Equity
Beginning Balance			$ 16,909,000,000	$ 15,585,000,000					$ 16,202,000,000	$ 14,878,000,000	$ 707,000,000	$ 707,000,000	$ 707,000,000	$ 707,000,000
Beginning Balance, Shares					843,814,000	820,152,000	(474,000)	(505,000)
Net Income After Dividends on Preferred and Preference Stock	916,000,000	817,000,000	1,942,000,000	1,822,000,000					1,942,000,000	1,822,000,000
Other comprehensive income (loss)	(19,000,000)	2,000,000	(11,000,000)	16,000,000					(11,000,000)	16,000,000
Stock issued, shares					18,634,000	18,994,000
Stock issued			692,000,000	650,000,000					692,000,000	650,000,000
Cash dividends on common stock			(1,193,000,000)	(1,114,000,000)					(1,193,000,000)	(1,114,000,000)
Other, shares							(45,000)	30,000
Other			1,000,000	3,000,000					1,000,000	3,000,000
Ending Balance	$ 18,340,000,000	$ 16,962,000,000	$ 18,340,000,000	$ 16,962,000,000					$ 17,633,000,000	$ 16,255,000,000	$ 707,000,000	$ 707,000,000	$ 707,000,000	$ 707,000,000
Ending Balance, Shares					862,448,000	839,146,000	(519,000)	(475,000)
Earnings per Share
As reported shares	860,000,000	836,000,000	854,000,000	829,000,000
Effect of options	8,000,000	6,000,000	7,000,000	4,000,000
Diluted shares	868,000,000	842,000,000	861,000,000	833,000,000
Stockholders' Equity (Textual) [Abstract]
Anti dilutive stock options	400,000	6,700,000	400,000	13,700,000
Assumed average stock price			$ 40.14	$ 38.01
Increase in effect of options		400,000		800,000