Leases (Details)	3 Months Ended	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jun. 30, 2019 ft²
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Option to renew		true
Operating Lease Cost (Cost resulting from lease payments)		$ 6,837,000	$ 1,490,000
Operating Lease - Operating Cash Flows (Fixed Payments)		5,572,000	1,519,000
Operating Lease - ROU assets	$ 12,173,000	35,873,000	12,173,000
Operating Lease - Liabilities	$ 13,032,000	$ 35,873,000	$ 13,032,000
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Operating Lease - Liabilities	Operating Lease - Liabilities	Operating Lease - Liabilities
Weighted Average Lease Term - Operating Leases		8 years 3 months 18 days	4 years 9 months 14 days
Weighted Average Discount Rate - Operating Leases	3.86%	4.55%	3.86%
Area of office space | ft²				54,910
Wallnut creek
Lessee, Lease, Description [Line Items]
Lease impairment and write-off of fixed assets and tenant improvements	$ 434,000
San Mateo
Lessee, Lease, Description [Line Items]
Lease impairment and write-off of fixed assets and tenant improvements	$ 625,000