Quarterly report pursuant to Section 13 or 15(d)

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

v3.8.0.1
Share-Based Compensation - Schedule of Share-Based Compensation (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total share-based compensation $ 22 $ 40 $ 81 $ 98
Capitalized share-based compensation (4) (7) (17) (13)
Total share-based compensation expense 18 33 64 85
Equity Awards [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total share-based compensation 10 7 25 37
Liability Awards [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total share-based compensation $ 12 $ 33 $ 56 $ 61