Quarterly report pursuant to Section 13 or 15(d)

Roll-forward of Common Stock, Additional Paid-in Capital, and Retained Earnings Accounts (Detail)

v2.4.0.6
Roll-forward of Common Stock, Additional Paid-in Capital, and Retained Earnings Accounts (Detail) (USD $)
In Millions, except Per Share data, unless otherwise specified
 3 Months Ended
Mar. 31, 2012
Mar. 31, 2011
Stockholders Equity Note [Roll Forward]    
Common stock purchases (7.1) (6.8)
Balance at beginning of period $ 7,035  
Net income 970 915
Common stock purchases (542) (501)
Balance at end of period 7,423  
Class A common stock
    
Stockholders Equity Note [Roll Forward]    
Balance at beginning of period   258
Common stock purchases (2.0) (2.0)
Stock award plans 2 1
Common stock issuances 1 1
Conversions of Class A to Class B common stock (5) (6)
Balance at end of period 236 252
Balance at beginning of period 3 3
Balance at end of period 3 3
Class B common stock
    
Stockholders Equity Note [Roll Forward]    
Balance at beginning of period   735
Common stock purchases (5.0) (5.0)
Conversions of Class A to Class B common stock 5 6
Balance at end of period 725 736
Balance at beginning of period 7 7
Balance at end of period 7 7
Additional Paid-in Capital
    
Stockholders Equity Note [Roll Forward]    
Balance at beginning of period 0 0
Stock award plans 210 143
Common stock issuances 63 58
Option premiums received (paid) 155 (25)
Common stock purchases (428) (176)
Balance at end of period 0 0
Retained Earnings
    
Stockholders Equity Note [Roll Forward]    
Balance at beginning of period 10,128 10,604
Net income 970 915
Dividends ($0.57 and $0.52 per share) (551) (518)
Common stock purchases (114) (325)
Balance at end of period $ 10,433 $ 10,676
Common stock, cash paid for dividends, per share $ 0.57 $ 0.52