Registration of securities issued in business combination transactions

Assets and Liabilities Measured at Fair Value (Details)

v2.4.0.8
Assets and Liabilities Measured at Fair Value (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Current assets:      
Interest rate swap arrangements (note 9)   $ 1 $ 2
Current liabilities:      
Interest rate swap arrangements (note 9)   13 61
Recurring
     
Current assets:      
Cash equivalents 314 424 493
Interest rate swap arrangements (note 9)   1 2
Current liabilities:      
Interest rate swap arrangements (note 9)   13 61
Long-term liabilities      
Debt (note 6) 3,703 3,626 2,636
Recurring | Level 1
     
Current assets:      
Cash equivalents 314 424 493
Recurring | Level 2
     
Current assets:      
Interest rate swap arrangements (note 9)   1 2
Current liabilities:      
Interest rate swap arrangements (note 9)   13 61
Long-term liabilities      
Debt (note 6) $ 3,703 $ 3,626 $ 2,636