Quarterly report pursuant to Section 13 or 15(d)

Activity in Deferred Compensation Program (Detail)

v2.4.0.6
Activity in Deferred Compensation Program (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2012
Dec. 31, 2011
Mar. 31, 2012
Treasury Stock [Member]
Mar. 31, 2011
Treasury Stock [Member]
Mar. 31, 2012
Deferred Compensation Obligations
Mar. 31, 2011
Deferred Compensation Obligations
Stockholders Equity Note [Roll Forward]            
Balance at beginning of period (2) (2) (2) (2)    
Reinvested dividends     0 0    
Benefit payments     0 0    
Balance at end of period (2) (2) (2) (2)    
Balance at beginning of period $ 7,423 $ 7,035 $ (88) $ (103) $ 88 $ 103
Reinvested dividends     (1) (1) 1 1
Benefit payments     13 19 (13) (19)
Balance at end of period $ 7,423 $ 7,035 $ (76) $ (85) $ 76 $ 85