Related-Party Transactions (Details) - USD ($) |
6 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|
Dec. 31, 2016 |
Jul. 01, 2016 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Related Party Transaction [Line Items] | |||||
| Related Party Transaction, Expenses from Transactions with Related Party | $ 117,000,000 | $ 201,000,000 | |||
| Revenue from Related Parties | $ 17,000,000 | $ 31,000,000 | $ 38,000,000 | ||
| Related Party Transaction, Purchases from Related Party | $ 10,000,000 | $ 13,000,000 | |||
| Corporate Overhead Allocated | 0 | ||||
| Related Party, License Agreement, Improvement License, Terms | 2 years | ||||
| TSA Expenses [Member] | |||||
| Related Party Transaction [Line Items] | |||||
| Related Party Transaction, Expenses from Transactions with Related Party | $ 13,000,000 | ||||