Long-term Debt - Components of Debt (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total long-term debt	$ 400,000,000	$ 400,000,000
Less: Unamortized deferred financing cost	(9,213,000)	(10,165,000)
Total debt, net	390,787,000	389,835,000
Line of Credit | Revolving credit facility
Debt Instrument [Line Items]
Total long-term debt	0	0
Senior Notes | Senior Notes due 2026
Debt Instrument [Line Items]
Total long-term debt	$ 400,000,000	$ 400,000,000