Debt - Summary of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Unamortized issuance costs and discount	$ (734)	$ (4,374)
Carrying amount	178,691	146,576
Less: current portion, net of unamortized issuance costs and discount of $0.0 million at September 30, 2021 and $1.9 million at December 31, 2020, respectively	(8,438)	(2,429)
Total long-term debt, net of current portion	170,253	144,147
Current portion ,net of unamortized discount and issuance costs	0	1,900
Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	31,300	0
Carrying amount	31,300	0
Term loan facility due 2026
Debt Instrument [Line Items]
Long-term debt	148,125	0
Carrying amount	147,391	0
Less: current portion, net of unamortized issuance costs and discount of $0.0 million at September 30, 2021 and $1.9 million at December 31, 2020, respectively	(8,400)
Total long-term debt, net of current portion	170,300
Term loan and security agreement due 2023 | Line of Credit
Debt Instrument [Line Items]
Carrying amount	0	146,576
Less: current portion, net of unamortized issuance costs and discount of $0.0 million at September 30, 2021 and $1.9 million at December 31, 2020, respectively		(2,400)
Total long-term debt, net of current portion		144,100
Term loan and security agreement due 2023 | Secured Debt
Debt Instrument [Line Items]
Long-term debt	$ 0	$ 150,950