Stockholder's Equity (Details 1) (USD $) Share data in Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Number of Common shares Issued [Member]	Jun. 30, 2011 Number of Common shares Issued [Member]	Jun. 30, 2012 Number of Common shares Treasury [Member]	Jun. 30, 2011 Number of Common shares Treasury [Member]	Jun. 30, 2012 Common Stockholders' Equity [Member]	Jun. 30, 2011 Common Stockholders' Equity [Member]	Jun. 30, 2012 Preferred and Preference Stock of Subsidiaries [Member]	Dec. 31, 2011 Preferred and Preference Stock of Subsidiaries [Member]	Jun. 30, 2011 Preferred and Preference Stock of Subsidiaries [Member]	Dec. 31, 2010 Preferred and Preference Stock of Subsidiaries [Member]
Changes in Stockholders' Equity
Beginning Balance			$ 18,285,000,000	$ 16,909,000,000					$ 17,578,000,000	$ 16,202,000,000	$ 707,000,000	$ 707,000,000	$ 707,000,000	$ 707,000,000
Beginning Balance, Shares					(865,664)	(843,814)	(539)	(474)
Net Income After Dividends on Preferred and Preference Stock	623,000,000	604,000,000	991,000,000	1,026,000,000					991,000,000	1,026,000,000
Other comprehensive income (loss)	(7,000,000)	4,000,000	(1,000,000)	8,000,000					(1,000,000)	8,000,000
Stock issued, shares					9,697	14,337
Stock issued			395,000,000	533,000,000					395,000,000	533,000,000
Cash dividends on common stock			(837,000,000)	(787,000,000)					(837,000,000)	(787,000,000)
Other			(2,000,000)						(2,000,000)
Other Share							(26)	(25)
Ending Balance	$ 18,831,000,000	$ 17,689,000,000	$ 18,831,000,000	$ 17,689,000,000					$ 18,124,000,000	$ 16,982,000,000	$ 707,000,000	$ 707,000,000	$ 707,000,000	$ 707,000,000
Ending Balance, Shares					(875,361)	(858,151)	(565)	(499)