Related Parties - Insurance Allocation Agreement (Details) - Directors and officers liability insurance - USD ($) $ in Millions		12 Months Ended
Jun. 07, 2017	Dec. 31, 2016
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Multi-employer insurance policy amount		$ 150.0
Subsequent event \| Liability insurance policy payment
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Liability insurance, conditional settlement payment amount	$ 32.0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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