Schedule - Valuation and Qualifying Accounts (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Valuation allowances on deferred tax assets written off against the deferred tax assets	$ 6,034	$ 1,176	$ 4,684
Accounts receivable allowances written off against related accounts receivables	$ 4,930	$ 2,126	$ 6,361