XML 90 R68.htm IDEA: XBRL DOCUMENT v3.21.2
Commitments (Details) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]      
Rent expenses under operating leases $ 683,000 $ 592,000 $ 548,000