Quarterly report pursuant to Section 13 or 15(d)

Revenues from Contracts with Customers - Schedule of Deferred Revenue Reconciliation (Details)

v3.8.0.1
Revenues from Contracts with Customers - Schedule of Deferred Revenue Reconciliation (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Change In Contract With Customer, Liability [Roll Forward]    
Deferred revenues, beginning of period $ 111 $ 73
Cash received but not yet recognized 120 61
Revenue recognized from prior period deferral (111) (71)
Deferred revenues, end of period $ 120 $ 63