Quarterly report pursuant to Section 13 or 15(d)

Cash, cash equivalents and investments - Narrative (Details)

v3.21.2
Cash, cash equivalents and investments - Narrative (Details) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Cash and Cash Equivalents [Abstract]          
Cash equivalents $ 34,900,000   $ 34,900,000   $ 64,000,000
Realized gains (losses) recognized on available-for-sale investments $ 0 $ (200,000) $ 0 $ 0