Total Equity and Earnings Per Share (Details) (USD $) In Billions, except Share data	6 Months Ended							6 Months Ended
	Jun. 30, 2011 Series E Preferred Stock.	Jun. 30, 2011 Series F Preferred Stock.	Jun. 30, 2011 Series C Preferred Stock.	Jun. 30, 2011 Series G	Jun. 30, 2011 Series G Preferred Stock.	Jun. 30, 2011 Common Stock	Dec. 31, 2010 Common Stock	Jun. 30, 2011 Treasury Stock	Jun. 30, 2011 Equity Units	Aug. 01, 2011 Equity Units
Class of stock disclosure
Retirement of debentures									$ 2.2
Common stock issued in connection with settlement of the stock purchase contract portion of the Equity Units (in shares)						1,904,632,947	147,124,067		2,400,000	1,200,000
The following table presents a roll forward of outstanding shares:
Shares issued, beginning of year (in shares)	400,000	300,000	100,000			147,124,067		6,660,908
Issuances (in shares)				20,000	20,000	100,066,640		11,678
Settlement of equity unit stock purchase contracts (in shares)						2,404,278
Shares exchanged (in shares)	(400,000)	(300,000)	(100,000)			1,655,037,962
Shares cancelled (in shares)					(20,000)
Shares issued, end of period (in shares)						1,904,632,947		6,672,586