Commitments and Contingencies - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Lessee, Lease, Description [Line Items]
Operating lease cost		$ 100,000		$ 100,000
Right-of-use asset	$ 38,705,000		$ 38,705,000		$ 39,890,000
Current Headquarters
Lessee, Lease, Description [Line Items]
Minimum monthly rental expense	$ 2,000,000.0		$ 3,900,000
Discount rate (as a percent)	12.00%		12.00%
Right-of-use asset	$ 38,700,000		$ 38,700,000		39,900,000
Operating lease liability	$ 44,483,000		44,483,000		$ 41,900,000
Building | Current Headquarters
Lessee, Lease, Description [Line Items]
Minimum monthly rental expense			$ 24,100
Annual rent increase (as a percent)	3.00%		3.00%
Building | Future Headquarters
Lessee, Lease, Description [Line Items]
Lease term	12 years		12 years
Minimum monthly rental expense			$ 600,000
Annual rent increase (as a percent)	3.00%		3.00%