Long-Term Debt - Summary of Long-Term Debt (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019	Sep. 29, 2017
Debt Instrument [Line Items]
Revolving credit facility		$ 324,400	$ 362,400
Second Lien Facility		200,000	200,000
Long-term Debt		524,400	562,400
Debt Instrument, Unamortized Discount		(1,814)	(2,415)	$ (4,000)
Unamortized Debt Issuance Expense		(3,728)	(4,957)	$ (8,200)
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net		518,858	555,028
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums	[1],[2]	$ 5,542	$ 7,372

[1] Discount and issuance costs of the Second Lien Facility are being amortized over the term of the underlying loan using the effective-interest method

[2] ssuance costs of the Credit Facility, which represent costs attributable to the access to credit over its contractual term, that have been presented as a component of Other assets (see Note 10) and are being amortized over the term of the Credit Facility using the straight-line method.