Quarterly report pursuant to Section 13 or 15(d)

Revenue (Contract Assets and Liabilities) (Details)

v3.20.2
Revenue (Contract Assets and Liabilities) (Details) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Dec. 31, 2019
Revenue from Contract with Customer [Abstract]          
Contract assets $ 802,000   $ 802,000   $ 1,089,000
Contract with customer, liability 15,900,000   15,900,000   $ 11,600,000
Contract with customer, liability, revenue recognized $ 4,200,000 $ 3,400,000 8,600,000 $ 8,300,000  
Contract with customer, performance obligation satisfied in previous period     $ 0 $ 0