Accrued Payroll and Benefits - Schedule of Accrued Payroll and Benefits (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Accrued bonuses	$ 8,233	$ 5,416
Accrued paid time off	1,990	2,067
Accrued payroll	7,472	9,133
Accrued other	4,790	4,565
Total accrued payroll and benefits	$ 22,485	$ 21,181