Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation - Schedule of Unrecognized Compensation Cost (Details)

v3.8.0.1
Share-Based Compensation - Schedule of Unrecognized Compensation Cost (Details)
$ in Millions
12 Months Ended
Dec. 31, 2017
USD ($)
Restricted Stock Share Awards [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Unrecognized compensation cost $ 7
Recognized over a weighted average period 1 year 6 months 1 day
Restricted Share Unit And Performance Stock Unit Awards [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Unrecognized compensation cost $ 44
Recognized over a weighted average period 1 year 6 months 1 day
Phantom Unit Awards [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Unrecognized compensation cost $ 49
Recognized over a weighted average period 1 year 1 month 1 day