Commitments and Contingencies - Narrative (Details)		1 Months Ended		3 Months Ended
	Jun. 30, 2017 USD ($)	Apr. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)	Mar. 31, 2021 USD ($) ft² reportingUnit	Sep. 30, 2021 USD ($) ft² renewalOption	Dec. 31, 2020 USD ($)	Apr. 30, 2020 ft²	Jan. 31, 2020 ft²	Feb. 28, 2017
Commitments and Contingencies [Line Items]
Area of real estate property (in square feet) | ft²					77,300
Number of options to extend | renewalOption					1
Asset retirement obligations					$ 300,000	$ 300,000
Future lease commitment					28,146,000
Term of contract		3 years	3 years						3 years
Capital lease obligations incurred		$ 300,000	$ 400,000
Percentage of eligible accounts receivable	80.00%
Indemnification Agreement
Commitments and Contingencies [Line Items]
Loss contingency accrual					0
Term Loan
Commitments and Contingencies [Line Items]
Borrowing capacity	$ 10,000,000
Stated interest rate	3.75%
Basis spread on variable rate (percent)	0.50%
Revolving Credit Facility
Commitments and Contingencies [Line Items]
Borrowing capacity	$ 5,000,000
Stated interest rate	4.25%
Basis spread on variable rate (percent)	1.00%
San Carlos, Califiornia
Commitments and Contingencies [Line Items]
Future lease commitment					100,000
Demand Deposits
Commitments and Contingencies [Line Items]
Non-current restricted cash					$ 1,000,000	$ 1,000,000
200-220 Penobscot
Commitments and Contingencies [Line Items]
Area of real estate property (in square feet) | ft²					28,200
400 Penobscot
Commitments and Contingencies [Line Items]
Area of real estate property (in square feet) | ft²					37,900
Renewal term					5 years
501 Chesapeake
Commitments and Contingencies [Line Items]
Area of real estate property (in square feet) | ft²					11,200
Number of options to extend | renewalOption					1
Renewal term					5 years
101 Saginaw
Commitments and Contingencies [Line Items]
Area of real estate property (in square feet) | ft²								29,900
Sublease
Commitments and Contingencies [Line Items]
Area of real estate property (in square feet) | ft²							3,400	26,500
San Carlos
Commitments and Contingencies [Line Items]
Area of real estate property (in square feet) | ft²				36,593
Number of options to extend | reportingUnit				1
Future lease commitment					$ 31,723,000
Annualized rent				$ 2,500,000
Annual rent increases (as a percent)				3.00%
Lease term				10 years
Renewal term				5 years
Security deposit				$ 500,000
San Carlos | Leaseholds and Leasehold Improvements
Commitments and Contingencies [Line Items]
Tenant improvement allowance				6,300,000
San Carlos | Asset under Construction
Commitments and Contingencies [Line Items]
Tenant improvement allowance				2,700,000
Annualized rent				$ 400,000