Quarterly report pursuant to Section 13 or 15(d)

Revenue Recognition - Changes in Contractual Liabilities Balance (Details)

v3.20.2
Revenue Recognition - Changes in Contractual Liabilities Balance (Details) - USD ($)
9 Months Ended 36 Months Ended
Sep. 30, 2020
Sep. 30, 2020
Contract with Customer, Liability [Abstract]    
Beginning balance $ 21,767,000  
Revenue recognized 18,376,000 $ 0
Ending balance $ 17,050,000 $ 17,050,000