Quarterly report pursuant to Section 13 or 15(d)

Revenue (Contract Assets and Liabilities) (Details)

v3.21.1
Revenue (Contract Assets and Liabilities) (Details) - USD ($)
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Dec. 31, 2020
Revenue from Contract with Customer [Abstract]      
Contract assets $ 470,000   $ 467,000
Contract with customer, liability 14,800,000   $ 16,400,000
Contract with customer, liability, revenue recognized 4,500,000 $ 3,700,000  
Contract with customer, performance obligation satisfied in previous period $ 0 $ 0