XML 27 R79.htm IDEA: XBRL DOCUMENT v2.4.0.6
Fair Value Measurements Fair Value Measurements - Debt (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt, carrying value $ 6,806 $ 6,157
Long-term debt, fair value   7,804
Fair Value, Inputs, Level 2 [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt, fair value $ 8,350