Quarterly report pursuant to Section 13 or 15(d)

Revenue (Contract Assets and Liabilities) (Details)

v3.21.2
Revenue (Contract Assets and Liabilities) (Details) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Revenue from Contract with Customer [Abstract]          
Contract assets $ 430,000   $ 430,000   $ 467,000
Contract with customer, liability 13,600,000   13,600,000   $ 16,400,000
Contract with customer, liability, revenue recognized $ 4,300,000 $ 4,200,000 10,900,000 $ 8,600,000  
Contract with customer, performance obligation satisfied in previous period     $ 0 $ 0