Debt Schedule of Debt Obligations (Details) - USD ($)		3 Months Ended		9 Months Ended
	Jul. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Mar. 10, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total debt outstanding		$ 746,583,000		$ 746,583,000			$ 728,525,000
Deferred finance fees		(12,033,000)		(12,033,000)			(14,222,000)
Net debt		734,550,000		734,550,000			714,303,000
Less current maturities		(1,280,000)		(1,280,000)			(1,280,000)
Long-term debt		733,270,000		733,270,000			713,023,000
Loss on extinguishment of debt	$ 4,000,000.0	0	$ 4,005,000	0	$ 4,005,000
Notes Payable
Debt Instrument [Line Items]
Total debt outstanding		2,561,000		2,561,000			3,525,000
2019 Credit Facility | Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Total debt outstanding		$ 269,022,000		$ 269,022,000			$ 250,000,000
Debt interest rate		4.10%		4.10%			4.20%
Increase in maximum borrowing capacity						$ 35,000,000.0
Maximum borrowing capacity						$ 385,000,000.0
Remaining borrowing capacity		$ 67,400,000		$ 67,400,000
Senior Secured Notes due 2024 | Senior Notes
Debt Instrument [Line Items]
Total debt outstanding		$ 475,000,000		$ 475,000,000			$ 475,000,000
Debt interest rate		10.00%		10.00%			10.00%