Revenue Recognition - Summary of Changes in Allowance for Credit Losses (Detail) $ in Thousands	6 Months Ended
	Mar. 31, 2022 USD ($)
Revenue From Contract With Customer [Abstract]
Balance at September 30, 2021	$ 4,779
Current period provision	2,167
Write-offs, net and other	(165)
Balance as of March 31, 2022	$ 6,781