Redeemable Noncontrolling Interest - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Temporary Equity [Abstract]    
Beginning balance $ 1,000 $ 1,000
Net income attributable to redeemable noncontrolling interest 16 16
Distributions to noncontrolling interests (16) (16)
Ending balance $ 1,000 $ 1,000