Voluntary Reorganization under Chapter 11 - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 14, 2019
Debt Instrument [Line Items]
Long-term debt	$ 445,055,000
Operating cash payments for bankruptcy-related transaction	24,900,000	$ 0	$ 0
Bankruptcy-related operating cash receipts	0
Interest expense on liabilities subject to compromise not accrued	$ 6,300,000
Revolving Credit Facility | Senior secured debtor-in-possession credit facility
Debt Instrument [Line Items]
Maximum borrowing capacity of credit facility				$ 425,000,000
DIP Revolving Loans | Revolving Credit Facility | Senior secured debtor-in-possession credit facility
Debt Instrument [Line Items]
Long-term debt				$ 236,200,000