v3.7.0.1
Stock-Based Compensation Equity Classified Share Based Awards (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting period for graded and cliff vesting options - minimum     1 year    
Vesting period for graded and cliff vesting options - maximum     5 years    
Share-based Compensation Arrangement by Share-based Payment Award, Award Expiration Minimum Range     5 years    
Share-based Compensation Arrangement by Share-based Payment Award, Award Expiration Maximum Range     10 years    
Allocated Share-based Compensation Expense $ 9 $ 8 $ 17 $ 15  
Restricted Stock [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number 6,332,956 [1]   6,332,956 [1]   4,869,648
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized $ 43   $ 43    
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition 1 year 8 months 12 days        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Total Fair Value     $ 19 16  
Performance Shares [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number 1,284,621   1,284,621   890,587
Allocated Share Based Compensation Expense Liability Classified Share-Based Awards $ 3 $ 0 $ 3 $ 2  
Director Plan [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number 63,075   63,075    
Common Stock, Capital Shares Reserved for Future Issuance 300,000   300,000    
Equity Plan [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number 6,269,881   6,269,881    
Common Stock, Capital Shares Reserved for Future Issuance 21,865,106   21,865,106    
May 16, 2017 [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term [2]     10 years    
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate [3]     33.00%    
February 15, 2017 [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term [2]     7 years 3 months 18 days    
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate [3]     40.00%    
[1] Includes 63,075 shares of restricted stock and restricted stock units outstanding under the Director Plans and 6,269,881 shares of restricted stock and restricted stock units outstanding under the Equity Plans
[2] Expected term calculated using historical exercise data.
[3] Volatility calculated using the implied volatility of our exchange traded stock options.