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Debt - Narrative (Details)		3 Months Ended					9 Months Ended		12 Months Ended
	Sep. 30, 2021 USD ($) entity	Sep. 30, 2021 USD ($) entity loan	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($) entity loan	Sep. 30, 2021 USD ($) entity loan	Sep. 30, 2020 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Oct. 02, 2019 USD ($)
Debt Instrument [Line Items]
Long-term debt	$ 326,286,000	$ 326,286,000					$ 326,286,000						$ 375,397,000
Amortization of debt issuance costs		492,000			$ 727,000		1,756,000	$ 2,219,000
Gain (loss) on extinguishment of debt		$ 968,000			$ 0		$ 2,032,000	$ 0
Number of entities | entity	2	2				2	2
Ownership interest in subsidiaries	50.00%	50.00%				50.00%	50.00%
Paycheck protection loans received, CARES Act | loan						3
Paycheck protection program loan amount, CARES Act						$ 9,800,000
Loans the SBA forgave, CARES Act | loan		1					2
Credit Agreement
Debt Instrument [Line Items]
Cash flow prepayment term							5 days
Term Loan Facility
Debt Instrument [Line Items]
Gain (loss) on extinguishment of debt		$ 0					$ (431,000)
Paycheck Protection Program
Debt Instrument [Line Items]
Gain (loss) on extinguishment of debt		968,000					2,463,000
Loan amount forgiven		$ 2,000,000					$ 5,000,000
Secured Debt | Credit Agreement
Debt Instrument [Line Items]
Debt instrument face amount														$ 475,000,000
Secured Debt | Term Loan Facility
Debt Instrument [Line Items]
Weighted average interest rate	5.15%	5.15%					5.15%
Repayments of debt							$ 20,612,000
Excess cash flow payment				$ 18,000,000			18,000,000
Optional prepayment			$ 5,444,000				5,444,000
Long-term debt	$ 310,944,000	$ 310,944,000					310,944,000						$ 355,000,000
Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	$ 0	0					0
Revolving Credit Facility | Secured Debt | Term Loan Facility
Debt Instrument [Line Items]
Debt instrument face amount														400,000,000
Revolving Credit Facility | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity														75,000,000
Debt instrument, LIBOR interest rate	0.084%
Revolving Credit Facility | Line of Credit | Revolving Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate	2.50%
Swing Line Loan | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity														$ 15,000,000
Interest Rate Swap | Secured Debt
Debt Instrument [Line Items]
Derivative, notional amount	$ 275,000,000	$ 275,000,000					$ 275,000,000
Forecast | Secured Debt | Term Loan Facility
Debt Instrument [Line Items]
Periodic payments									$ 18,300,000	$ 22,300,000	$ 16,200,000	$ 24,700,000

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