COMPOSITION OF CERTAIN BALANCE SHEET ACCOUNTS - Summary of Allowance for Losses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 1,773	$ 1,397	$ 1,109
Provision	(830)	731	290
Bad debt write-offs	0	(355)	(2)
Acquisition	30	0	0
Divestiture	(32)	0	0
Ending balance	$ 941	$ 1,773	$ 1,397