Quarterly report pursuant to Section 13 or 15(d)

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

v3.2.0.727
Roll-forward of Common Stock, Additional Paid-in Capital, and Retained Earnings Accounts (Detail) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Stockholders Equity Note [Roll Forward]        
Common stock purchases     (13.5) (13.7)
Balance at beginning of period     $ 2,141  
Net income $ 1,230 $ 454 2,256 $ 1,365
Common stock purchases     (1,358) $ (1,363)
Balance at end of period $ 1,950   $ 1,950  
Class A common stock        
Stockholders Equity Note [Roll Forward]        
Balance at beginning of period     201.0 212.0
Common stock purchases     (2.0) (3.0)
Stock award plans     4.0 4.0
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures     $ 0 $ 0
Common stock issuances     1.0 1.0
Conversions of Class A to Class B common stock     (5.0) (6.0)
Stock Issued During Period, Value, Conversion of Convertible Securities     $ 0 $ 0
Balance at end of period 199.0 208.0 199.0 208.0
Balance at beginning of period     $ 2 $ 2
Common stock issuances     0 0
Common stock purchases     0 0
Balance at end of period $ 2 $ 2 $ 2 $ 2
Class B common stock        
Stockholders Equity Note [Roll Forward]        
Balance at beginning of period     705.0 712.0
Common stock purchases     (12.0) (11.0)
Conversions of Class A to Class B common stock     (5.0) (6.0)
Stock Issued During Period, Value, Conversion of Convertible Securities     $ 0 $ 0
Balance at end of period 698.0 707.0 698.0 707.0
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     265 232
Common stock issuances     173 147
Option premiums received (paid)     (46) (102)
Common stock purchases     (392) (481)
Balance at end of period 0 0 0 0
Retained Earnings        
Stockholders Equity Note [Roll Forward]        
Balance at beginning of period     5,726 6,925
Net income     2,256 1,365
Dividends ($0.57 and $0.52 per share)     (1,348) (1,253)
Common stock purchases     (966) (882)
Balance at end of period $ 5,668 $ 6,155 $ 5,668 $ 6,155
Common stock, cash paid for dividends, per share     $ 1.46 $ 1.34
Options Held [Member]        
Stockholders Equity Note [Roll Forward]        
Option premiums received (paid)     $ (46) $ (102)