Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Additional Information (Details)

v3.20.4
Fair Value Measurements - Additional Information (Details) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Fair Value Disclosures [Abstract]    
Fair value, assets, level 1 to level 2 transfers, amount $ 0 $ 0
Fair value, assets, level 2 to level 1 transfers, amount 0 0
Fair value, measurement with unobservable inputs reconciliation, recurring basis, asset, transfers, net 0 0
Available-for-sale securities $ 108,662,000 $ 0