XML 63 R50.htm IDEA: XBRL DOCUMENT v3.5.0.2
Incentive Plans Incentive Plans (Stock-based compensation) (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Deferred Compensation Arrangement with Individual, Compensation Expense $ 31 $ 26 $ 84 $ 87  
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized 138   $ 138    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period     3 years    
Restricted Stock Liability Awards [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized 36   $ 36    
Accounts Payable, Current $ 17   $ 17   $ 16