Quarterly report pursuant to Section 13 or 15(d)

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

v2.4.0.8
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 9 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Stockholders Equity Note [Roll Forward]        
Common stock purchases     (20.6) (33.3)
Balance at beginning of period     $ 6,474  
Net income 1,214 1,097 2,579 3,205
Common stock purchases     (2,042) (2,844)
Balance at end of period 5,627   5,627  
Class A common stock
        
Stockholders Equity Note [Roll Forward]        
Balance at beginning of period     212 225
Common stock purchases     (4.0) (6.0)
Stock award plans     4 6
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures     0 0
Common stock issuances     2 3
Conversions of Class A to Class B common stock     (11) (14)
Stock Issued During Period, Value, Conversion of Convertible Securities     0 0
Balance at end of period 203 214 203 214
Balance at beginning of period     2 3
Common stock issuances     0 0
Common stock purchases     0 (1)
Balance at end of period 2 2 2 2
Class B common stock
        
Stockholders Equity Note [Roll Forward]        
Balance at beginning of period     712 729
Common stock purchases     (17.0) (27.0)
Conversions of Class A to Class B common stock     (11) (14)
Stock Issued During Period, Value, Conversion of Convertible Securities     0 0
Balance at end of period 706 716 706 716
Balance at beginning of period     7 7
Common stock purchases     0 0
Balance at end of period 7 7 7 7
Additional Paid-in Capital
        
Stockholders Equity Note [Roll Forward]        
Balance at beginning of period     0 0
Stock award plans     359 493
Common stock issuances     218 216
Option premiums received (paid)     53 (196)
Common stock purchases     (630) (513)
Balance at end of period 0 0 0 0
Retained Earnings
        
Stockholders Equity Note [Roll Forward]        
Balance at beginning of period     6,925 7,997
Net income     2,579 3,205
Dividends ($0.57 and $0.52 per share)     (1,863) (1,770)
Common stock purchases     (1,412) (2,330)
Balance at end of period 6,229 7,102 6,229 7,102
Common stock, cash paid for dividends, per share     $ 2.01 $ 1.86
Options Held [Member]
        
Stockholders Equity Note [Roll Forward]        
Option premiums received (paid)     $ (53) $ 196