Related Party Transactions - Related Party Receivable and Payable (Details) - USD ($) $ in Millions |
Jun. 30, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Related Party Transaction [Line Items] | ||
| Due from related parties | $ 8.0 | $ 13.2 |
| Due to related parties | 124.2 | 10.8 |
| Other Current Assets [Member] | ||
| Related Party Transaction [Line Items] | ||
| Due from related parties | 8.0 | 13.2 |
| Other Current Liabilities [Member] | ||
| Related Party Transaction [Line Items] | ||
| Due to related parties | 23.5 | 10.8 |
| Contingent Liabilities [Member] | ||
| Related Party Transaction [Line Items] | ||
| Due to related parties | $ 100.7 | $ 0.0 |