Debt - Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Less – unamortized original issue discount	$ (3,406)		$ (5,346)
Less – deferred financing costs		$ (3,700)
Total debt, net of unamortized discounts	374,719		351,217
Current portion of long-term debt, net of unamortized discounts	(237,500)		(14,063)
Long-term debt, net of unamortized discounts	137,219		337,154
2021 Credit Agreement
Debt Instrument [Line Items]
Less – deferred financing costs	(3,400)
2021 Credit Agreement | 2021 Term Loan
Debt Instrument [Line Items]
Carrying Value	148,125
Less – deferred financing costs	(3,406)
Total debt, net of unamortized discounts	144,719	$ 150,000
2018 Credit Agreement | 2018 Term Loan
Debt Instrument [Line Items]
Carrying Value			126,563
Less – deferred financing costs			(1,155)
Total debt, net of unamortized discounts			125,408
Senior Convertible Notes 2016
Debt Instrument [Line Items]
Carrying Value	230,000		230,000
Less – unamortized original issue discount	0		(3,021)
Less – deferred financing costs	0		(1,170)
Total debt, net of unamortized discounts	230,000		$ 225,809
Current portion of long-term debt, net of unamortized discounts	$ (230,000)