Total Equity and Other Comprehensive Income (Rollforward of Total Equity) (Details) (USD $)	3 Months Ended				9 Months Ended						9 Months Ended				9 Months Ended						9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011		Dec. 31, 2011		Sep. 30, 2012 Common Stock [Member]	Sep. 30, 2011 Common Stock [Member]		Dec. 31, 2010 Common Stock [Member]	Sep. 30, 2012 Preferred Stock Including Additional Paid in Capital [Member]		Sep. 30, 2011 Preferred Stock Including Additional Paid in Capital [Member]		Jun. 30, 2012 Preferred Stock Including Additional Paid in Capital [Member]		Sep. 30, 2012 Common Stock Including Additional Paid in Capital [Member]	Sep. 30, 2011 Common Stock Including Additional Paid in Capital [Member]		Sep. 30, 2012 Retained Earnings [Member]	Sep. 30, 2011 Retained Earnings [Member]		Sep. 30, 2012 Accumulated Other Comprehensive Income (Loss) [Member]	Sep. 30, 2011 Accumulated Other Comprehensive Income (Loss) [Member]		Sep. 30, 2012 Treasury Stock [Member]	Sep. 30, 2011 Treasury Stock [Member]		Sep. 30, 2012 Noncontrolling Interest [Member]	Sep. 30, 2011 Noncontrolling Interest [Member]		Sep. 30, 2012 Series P [Member]		Sep. 30, 2011 Series O [Member]		Sep. 30, 2012 Series Q [Member]
Beginning Balance					$ 37,246,000,000		$ 32,838,000,000				$ 2,683,000,000	$ 2,682,000,000	[1]	$ 2,682,000,000	$ 1,637,000,000		$ 647,000,000				$ 12,072,000,000	$ 12,057,000,000		$ 18,253,000,000	$ 15,859,000,000		$ (105,000,000)	$ (431,000,000)		$ (487,000,000)	$ (572,000,000)		$ 3,193,000,000	$ 2,596,000,000
Beginning Balance (in shares)											527,000,000	526,000,000	[1]	526,000,000
Net income	925,000,000		834,000,000		2,282,000,000		2,578,000,000																	2,295,000,000	2,580,000,000								(13,000,000)	(2,000,000)
Other comprehensive income (loss), net of tax	589,000,000		328,000,000		1,096,000,000		828,000,000																				1,096,000,000	828,000,000
Cash dividends declared
Common					(608,000,000)		(421,000,000)																	(608,000,000)	(421,000,000)
Preferred					(125,000,000)		(32,000,000)																	(125,000,000)	(32,000,000)
Preferred stock discount accretion															2,000,000		1,000,000							(2,000,000)	(1,000,000)
Common stock activity					43,000,000		6,000,000	[2]			6,000,000										37,000,000	6,000,000	[2]
Common stock activity, shares					1,000,000		500,000
Treasury stock activity					20,000,000		14,000,000	[2]													51,000,000	(23,000,000)	[2]							(31,000,000)	37,000,000	[2]
Treasury stock activity, shares					1,000,000		(500,000)
Other					(72,000,000)		443,000,000														(11,000,000)	14,000,000											(61,000,000)	429,000,000
Ending Balance	41,802,000,000		37,242,000,000	[1]	41,802,000,000		37,242,000,000	[1]			2,689,000,000	2,682,000,000	[1]	2,682,000,000	3,559,000,000		1,636,000,000	[1]			12,149,000,000	12,054,000,000	[1]	19,813,000,000	17,985,000,000	[1]	991,000,000	397,000,000	[1]	(518,000,000)	(535,000,000)	[1]	3,119,000,000	3,023,000,000	[1]
Ending Balance, (in shares)											529,000,000	526,000,000	[1]	526,000,000
Par value less than $.5 million at each date	500,000		500,000		500,000		500,000		500,000
Common Stock, Dividends, Per Share, Declared					$ 1.15		$ 0.80
Preferred Stock, Shares Issued																																				15,000		10,000		4,500
Preferred Stock issued, value		[3]				[3]				[3]					$ 438,000,000	[4]	$ 988,000,000	[5]	$ 1,482,000,000	[6]																$ 1,482,000,000	[6]	$ 988,000,000	[5]	$ 438,000,000	[4]
Preferred Stock, Par or Stated Value Per Share																																				$ 1		$ 1		$ 1

[1] The par value of our preferred stock outstanding was less than $.5 million at each date and, therefore, is excluded from this presentation.

[2] Common and net treasury stock activity totaled less than .5 million shares.

[3] Par value less than $.5 million at each date.

[4] 4,500 Series Q preferred shares with a $1 par value were issued on September 21, 2012.

[5] 10,000 Series O preferred shares with a $1 par value were issued on July 20, 2011.

[6] 15,000 Series P preferred shares with a $1 par value were issued on April 24, 2012.