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
Mar. 31, 2014
Mar. 31, 2013
Stockholders Equity Note [Roll Forward]    
Common stock purchases (6.8) (12.2)
Balance at beginning of period $ 6,474  
Net income 911 1,037
Common stock purchases (659) (1,013)
Balance at end of period 6,247  
Class A common stock
    
Stockholders Equity Note [Roll Forward]    
Balance at beginning of period   225
Common stock purchases (1.0) (2.0)
Stock award plans 2 3
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures 0 0
Common stock issuances 1 1
Conversions of Class A to Class B common stock (3) (6)
Stock Issued During Period, Value, Conversion of Convertible Securities 0 0
Balance at end of period 211 221
Balance at beginning of period 2 3
Common stock issuances 0 0
Common stock purchases 0 (1)
Balance at end of period 2 2
Class B common stock
    
Stockholders Equity Note [Roll Forward]    
Balance at beginning of period   729
Common stock purchases (6.0) (10.0)
Conversions of Class A to Class B common stock 3 6
Stock Issued During Period, Value, Conversion of Convertible Securities 0 0
Balance at end of period 709 725
Balance at beginning of period 7 7
Common stock purchases 0 0
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 97 216
Common stock issuances 78 70
Option premiums received (paid) 1 (100)
Common stock purchases (176) (186)
Balance at end of period 0 0
Retained Earnings
    
Stockholders Equity Note [Roll Forward]    
Balance at beginning of period 6,925 7,997
Net income 911 1,037
Dividends ($0.57 and $0.52 per share) (626) (594)
Common stock purchases (483) (826)
Balance at end of period $ 6,727 $ 7,614
Common stock, cash paid for dividends, per share $ 0.67 $ 0.62