XML 74 R62.htm IDEA: XBRL DOCUMENT v3.21.2
Revenue - Contract Balances (Details) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2021
Dec. 31, 2020
Revenue      
Contract liabilities $ (258,000) $ (258,000) $ (374,000)
Revenue recognized, included in contract assets $ 12,000 $ 260,000