Debt - Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 13, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Less - unamortized original issue discount	$ (3,595)		$ (5,346)
Total debt, net of unamortized discounts	375,475		351,217
Current portion of long-term debt, net of unamortized discounts	(236,570)		(14,063)
Long-term debt, net of unamortized discounts	138,905		337,154
2021 Credit Agreement
Debt Instrument [Line Items]
Less – deferred financing costs	(3,700)
2021 Credit Agreement \| 2021 Term Loan
Debt Instrument [Line Items]
Total long-term debt, gross	150,000
Less – deferred financing costs	(3,595)
Total debt, net of unamortized discounts	146,405	$ 150,000
2018 Credit Agreement \| 2018 Term Loan
Debt Instrument [Line Items]
Total long-term debt, gross			126,563
Less – deferred financing costs			(1,155)
Total debt, net of unamortized discounts			125,408
Senior Convertible Notes 2016
Debt Instrument [Line Items]
Total long-term debt, gross	230,000		230,000
Less - unamortized original issue discount	(671)		(3,021)
Less – deferred financing costs	(259)		(1,170)
Total debt, net of unamortized discounts	229,070		$ 225,809
Current portion of long-term debt, net of unamortized discounts	$ (229,100)

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount of debt discount to be amortized after one year or the normal operating cycle, if longer.

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Amount, after accumulated amortization, of debt issuance costs classified as noncurrent. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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