Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies - Textual (Details)

v3.20.2
Commitments and Contingencies - Textual (Details)
1 Months Ended 9 Months Ended 12 Months Ended
Jun. 30, 2017
USD ($)
Apr. 30, 2017
USD ($)
Feb. 28, 2017
USD ($)
Sep. 30, 2020
USD ($)
ft²
security
numberOfRenewalOption
Dec. 31, 2019
USD ($)
Apr. 30, 2020
ft²
Jan. 31, 2020
ft²
Commitments and Contingencies [Line Items]              
Area of real estate property (square feet) | ft²       77,300      
Number of buildings leased | security       4      
Number of options to extend | numberOfRenewalOption       2      
Renewal term       5 years      
Asset retirement obligations       $ 200,000 $ 200,000    
Accretion expense related to asset retirement obligation       0 0    
Capital lease obligations incurred   $ 300,000 $ 400,000        
Term of contract   3 years 3 years        
Credit Availability Concentration Risk [Member]              
Commitments and Contingencies [Line Items]              
Concentration risk, percentage 80.00%            
Indemnification Agreement [Member]              
Commitments and Contingencies [Line Items]              
Loss contingency accrual       $ 0      
Term Loan [Member]              
Commitments and Contingencies [Line Items]              
Borrowing capacity $ 10,000,000.0            
Basis spread on variable rate (percent)       0.50%      
Stated interest rate       3.75%      
Revolving Credit Facility [Member]              
Commitments and Contingencies [Line Items]              
Borrowing capacity $ 5,000,000.0            
Basis spread on variable rate (percent)       1.00%      
Stated interest rate       4.25%      
Demand Deposits [Member]              
Commitments and Contingencies [Line Items]              
Non-current restricted cash       $ 1,100,000 $ 1,100,000    
200-220 Penobscot [Member]              
Commitments and Contingencies [Line Items]              
Area of real estate property (square feet) | ft²       28,200      
400 Penobscot [Member]              
Commitments and Contingencies [Line Items]              
Area of real estate property (square feet) | ft²       37,900      
501 Chesapeake [Member]              
Commitments and Contingencies [Line Items]              
Area of real estate property (square feet) | ft²       11,200      
101 Saginaw [Member]              
Commitments and Contingencies [Line Items]              
Area of real estate property (square feet) | ft²             29,900
Sublease [Member]              
Commitments and Contingencies [Line Items]              
Area of real estate property (square feet) | ft²           3,400 26,500