Leases - Additional Information (Details) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($) lease	Mar. 31, 2020 USD ($) lease	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Operating Leased Assets [Line Items]
Operating right of use assets	$ 8,759				$ 8,759		$ 155
Operating lease liability	$ 8,787				$ 8,787
Weighted-average remaining lease term (in years)	4 years 1 month 6 days				4 years 1 month 6 days
Average discount rate (as a percent)	3.60%				3.60%
Impairment loss					$ 0	$ 6,220
Gain on settlement					0	5,706
Operating lease liability-long term	$ 6,479				6,479		19
Current portion of operating lease liabilities	2,308				2,308		$ 115
Operating cash flows from operating leases	$ 723	$ 115			$ 1,506	961
Notes Payable, Other Payables | Lease Settlement Payable
Operating Leased Assets [Line Items]
Interest rate			4.00%
Notes payable			$ 100
New York City Headquarter
Operating Leased Assets [Line Items]
Operating lease liability		6,400				6,400
Number of leases | lease			2
Impairment loss			$ 5,300
Gain on settlement		4,900
Operating lease liability-long term			5,800
Current portion of operating lease liabilities		600				$ 600
Operating cash flows from operating leases		$ 1,500
Terminated and Vacated Lease
Operating Leased Assets [Line Items]
Operating lease liability			900
Number of leases | lease				1
Impairment loss				$ 900
Gain on settlement			$ 800