XML 68 R54.htm IDEA: XBRL DOCUMENT v3.20.4
Credit Losses - Summary of Allowance for Credit Losses Related to Accounts Receivable and Changes (Detail) - USD ($)
3 Months Ended 12 Months Ended
Dec. 31, 2020
Sep. 30, 2020
Jun. 30, 2020
Mar. 31, 2020
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Allowance For Doubtful Accounts Receivable Rollforward              
Beginning Balance $ 10,996,000 $ 12,122,000 $ 7,571,000 $ 6,516,000 $ 6,516,000    
Provision for expected credit losses     4,551,000 1,055,000 5,606,000 $ 5,683,000 $ 0
Write-offs (154,000) (1,126,000)          
Ending Balance $ 10,842,000 $ 10,996,000 $ 12,122,000 $ 7,571,000 $ 10,842,000 $ 6,516,000