Annual report pursuant to Section 13 and 15(d)

Equity - Equity-based Compensation Expense and Fair Value of Shares Vested (Details)

v3.10.0.1
Equity - Equity-based Compensation Expense and Fair Value of Shares Vested (Details) - 2013 Plan [Member] - Restricted Incentive [Member] - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Equity-based compensation expense $ 10 $ 11 $ 10
Fair value of awards vested on vesting date $ 7 $ 5 $ 14