Quarterly report pursuant to Section 13 or 15(d)

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

v3.5.0.2
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 12 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Dec. 31, 2015
Stockholders Equity Note [Roll Forward]          
Common stock purchases     (13.3)    
Balance at beginning of period     $ 2,470    
Net income $ 1,269 $ 1,230 2,400 $ 2,256  
Common stock purchases     (1,355)    
Balance at end of period $ 2,626   $ 2,626   $ 2,470
Class A common stock          
Stockholders Equity Note [Roll Forward]          
Balance at beginning of period     194.0 201.0 201.0
Common stock purchases     (3.0) (2.0)  
Stock award plans     4.0 4.0  
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures     $ 0 $ 0  
Common stock issuances     2.0 1.0  
Conversions of Class A to Class B common stock     (8.0) (5.0)  
Stock Issued During Period, Value, Conversion of Convertible Securities     $ 0 $ 0  
Balance at end of period 189.0 199.0 189.0 199.0 194.0
Balance at beginning of period     $ 2 $ 2 $ 2
Common stock issuances     0 0  
Common stock purchases     0 0  
Balance at end of period $ 2 $ 2 $ 2 $ 2 $ 2
Class B common stock          
Stockholders Equity Note [Roll Forward]          
Balance at beginning of period     693.0 705.0 705.0
Common stock purchases     (10.0) (12.0)  
Conversions of Class A to Class B common stock     (8.0) (5.0)  
Stock Issued During Period, Value, Conversion of Convertible Securities     $ 0 $ 0  
Balance at end of period 691.0 698.0 691.0 698.0 693.0
Balance at beginning of period     $ 7 $ 7 $ 7
Common stock purchases     0 0  
Balance at end of period $ 7 $ 7 7 7 7
Additional Paid-in Capital          
Stockholders Equity Note [Roll Forward]          
Balance at beginning of period     0 0 0
Stock award plans     289 265  
Common stock issuances     168 173  
Option premiums received (paid)     104 (46)  
Common stock purchases     (561) (392)  
Balance at end of period 0 0 0 0 0
Retained Earnings          
Stockholders Equity Note [Roll Forward]          
Balance at beginning of period     6,001 5,726 5,726
Net income     2,400 2,256  
Dividends ($0.57 and $0.52 per share)     (1,409) (1,348)  
Common stock purchases     (769) (966)  
Balance at end of period $ 6,223 $ 5,668 $ 6,223 $ 5,668 $ 6,001
Common stock, cash paid for dividends, per share     $ 1.56 $ 1.46