Leases (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021 USD ($) ft²	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) ft² item	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) ft²	Feb. 28, 2019 ft²
Lessee, Lease, Description [Line Items]
Area leased, sublease agreement | ft²	33,019		33,019			20,433
Number of lease financing arrangements | item			2
Amortization expense	$ 300	$ 300	$ 500	$ 500
Sub-subleased | ft²					8,115
Operating Leases:
Gross cost	4,329		4,329		$ 4,277
Accumulated amortization	(3,042)		(3,042)		(2,623)
Property and equipment, net	1,287		1,287		1,654
Current portion of lease liabilities	$ 647		$ 647		$ 603
Financial position	Current portion of lease liabilities		Current portion of lease liabilities		Current portion of lease liabilities
Other liabilities	$ 2,559		$ 2,559		$ 2,894
Financial position	Other liabilities		Other liabilities		Other liabilities
Total operating lease liabilities	$ 3,206		$ 3,206		$ 3,497
Operating Leases
Operating Leases:
Gross cost	5,240		5,240		5,240
Accumulated amortization	(1,450)		(1,450)		(1,111)
Property and equipment, net	$ 3,790		$ 3,790		$ 4,129