Quarterly report pursuant to Section 13 or 15(d)

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

v3.7.0.1
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, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Stockholders Equity Note [Roll Forward]        
Balance at beginning of period     $ 405  
Net income $ 1,384 $ 1,269 2,542 $ 2,400
Balance at end of period $ 1,244   $ 1,244  
Class A common stock        
Stockholders Equity Note [Roll Forward]        
Balance at beginning of period     180 194
Common stock purchases     (2) (3)
Stock award plans     4 4
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures     $ 0 $ 0
Common stock issuances     1 2
Conversions of Class A to Class B common stock     (5) (8)
Stock Issued During Period, Value, Conversion of Convertible Securities     $ 0 $ 0
Balance at end of period 178 189 178 189
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     689 693
Common stock purchases     (6) (10)
Conversions of Class A to Class B common stock     (5) (8)
Stock Issued During Period, Value, Conversion of Convertible Securities     $ 0 $ 0
Balance at end of period 688 691 688 691
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     157 289
Common stock issuances     203 168
Option premiums received (paid)     52 104
Common stock purchases     (412) (561)
Balance at end of period 0 0 0 0
Retained Earnings        
Stockholders Equity Note [Roll Forward]        
Balance at beginning of period     4,879 6,001
Net income     2,542 2,400
Dividends ($1.66 and $1.56 per share)     (1,495) (1,409)
Common stock purchases     (489) (769)
Balance at end of period $ 5,437 $ 6,223 $ 5,437 $ 6,223
Common stock, cash paid for dividends, per share     $ 1.66 $ 1.56
Options Held [Member]        
Stockholders Equity Note [Roll Forward]        
Option premiums received (paid)     $ 52 $ 104