Registration of securities issued in business combination transactions

Financial assets and liabilities measured at fair value on a recurring basis (Details)

v3.21.4
Financial assets and liabilities measured at fair value on a recurring basis (Details) - USD ($)
Sep. 30, 2021
Dec. 31, 2020
Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash Equivalents $ 33,138,000 $ 9,424,000 $ 8,761,000
Long-term investments 3,044,000 6,210,000 250,000
Current Liabilities, fair value   (550,000)  
Total 39,043,000 17,843,000 18,461,000
Short-term investments 2,861,000 2,759,000 8,694,000
Money Market Funds [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash Equivalents 33,138,000 9,424,000 8,761,000
Corporate Notes/Bonds [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Long-term investments 2,794,000 5,605,000  
Short-term investments 2,861,000 2,059,000  
Convertible Debt Securities [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Long-term investments 250,000 605,000 250,000
Commercial Paper [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Short-term investments   700,000  
Fair Value, Inputs, Level 1 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash Equivalents 33,138,000 9,424,000 8,761,000
Total 33,138,000 9,424,000 8,761,000
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash Equivalents 33,138,000 9,424,000 8,761,000
Fair Value, Inputs, Level 2 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Long-term investments 2,794,000 5,605,000  
Total 5,655,000 8,364,000 9,450,000
Short-term investments 2,861,000 2,759,000 9,450,000
Fair Value, Inputs, Level 2 [Member] | Corporate Notes/Bonds [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Long-term investments 2,794,000 5,605,000  
Short-term investments 2,861,000 2,059,000 8,694,000
Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Short-term investments   700,000 8,694,000
Fair Value, Inputs, Level 3 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Long-term investments 250,000 605,000 250,000
Current Liabilities, fair value   (550,000)  
Total 250,000 55,000 250,000
Fair Value, Inputs, Level 3 [Member] | Convertible Debt Securities [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Long-term investments $ 250,000 605,000 $ 250,000
Fair Value, Inputs, Level 3 [Member] | Accrued Consideration [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Current Liabilities, fair value   $ (550,000)