Quarterly report pursuant to Section 13 or 15(d)

Revenue Contract Assets and Liabilities (Details)

v3.20.1
Revenue Contract Assets and Liabilities (Details) - USD ($)
3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Dec. 31, 2019
Revenue from Contract with Customer [Abstract]      
Contract assets $ 907,000   $ 1,089,000
Contract with customer, liability 11,400,000   $ 11,600,000
Contract with customer, liability, revenue recognized 3,700,000 $ 3,700,000  
Contract with customer, performance obligation satisfied in previous period $ 0 $ 0