EPS under Basic and Diluted Computations (Detail) (USD $) In Millions, except Per Share data	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Earnings Per Share Disclosure [Line Items]
Net income available to common stockholders	$ 220	[1]	$ 124	[1]	$ 701	[1]	$ 335	[1]
Weighted-average common shares outstanding - basic	1,228		1,192		1,213		1,189
Common stock equivalent shares related to stock incentive plans	1		2		3		3
Weighted-average common shares outstanding - diluted	1,229	[2]	1,194	[2]	1,216	[2]	1,192	[2]
Basic EPS	$ 0.18		$ 0.10		$ 0.58		$ 0.28
Diluted EPS	$ 0.18		$ 0.10		$ 0.57		$ 0.28

[1] Net income available to participating securities (unvested restricted shares) was not material for the third quarters and first nine months of 2011 or 2010.

[2] Antidilutive stock options and restricted stock awards excluded from the calculation of diluted EPS totaled 50 million and 49 million shares for the third quarters of 2011 and 2010, respectively, and 48 million and 40 million shares for the first nine months of 2011 and 2010, respectively.