Goodwill and Intangible Assets - Future Amortization Expense of Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense of intangible assets, remainder of 2021	$ 294
Amortization expense of intangible assets, 2022	1,177
Amortization expense of intangible assets, 2023	1,177
Amortization expense of intangible assets, 2024	1,177
Amortization expense of intangible assets, 2025	1,177
Amortization expense of intangible assets, thereafter	407
Intangible assets, net	$ 5,409	$ 3,377	$ 10,344	$ 12,381