v2.4.0.6
Equity (Details 2) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Accumulated Other Comprehensive Income (Loss), Net of Tax      
Balance at end of period $ (610) $ 583  
Accumulated Other Comprehensive (Loss) (Note 23)
      
Accumulated Other Comprehensive Income (Loss), Net of Tax      
Balance at beginning of period 583 319 (811)
Other comprehensive income (loss) (1,224) 269 1,105
Income tax benefit (expense) 31 (5) 25
Balance at end of period (610) 583 319
Foreign exchange translation adjustment
      
Accumulated Other Comprehensive Income (Loss), Net of Tax      
Balance at beginning of period 670 423 (639)
Other comprehensive income (loss) (1,130) 247 1,062
Balance at end of period (460) 670 423
Deferred gain (loss) on hedging activities
      
Accumulated Other Comprehensive Income (Loss), Net of Tax      
Balance at beginning of period (2) (5) (80)
Other comprehensive income (loss) (33) 4 55
Income tax benefit (expense) 11 (1) 20
Balance at end of period (24) (2) (5)
Treasury Rate Lock Contracts
      
Accumulated Other Comprehensive Income (Loss), Net of Tax      
Balance at beginning of period   (7) (9)
Other comprehensive income (loss)   6 2
Income tax benefit (expense)   1  
Balance at end of period     (7)
Pension and other postretirement liability adjustment
      
Accumulated Other Comprehensive Income (Loss), Net of Tax      
Balance at beginning of period (83) (90) (79)
Other comprehensive income (loss) (61) 12 (17)
Income tax benefit (expense) 20 (5) 6
Balance at end of period (124) (83) (90)
Unrealized gain (loss) on Investments
      
Accumulated Other Comprehensive Income (Loss), Net of Tax      
Balance at beginning of period     (4)
Other comprehensive income (loss)     3
Income tax benefit (expense)     (1)
Balance at end of period $ (2) $ (2) $ (2)