Accounts Receivable - Schedule of Changes in Estimate of Credit Losses for Trade Accounts Receivable (Detail) - Trade Accounts Receivable [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2021 USD ($)
Accounts Notes And Loans Receivable [Line Items]
Balance at December 31, 2020	$ 31,596
Current period provision	2,110
Write-offs	(4,164)
Recoveries	480
Balance at September 30, 2021	$ 30,022