INCOME TAXES - Components of Net Deferred Income Tax Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Deferred tax assets:
Accrued liabilities and reserves	$ 38,820	$ 39,232
Tax loss and credit carryforwards	20,506	20,436
Capitalized research and development	10,854	8,446
Inventory	17,089	14,274
Lease obligations	42,544	46,179
Other	1,939	1,121
Deferred tax assets	131,752	129,688
Deferred tax liabilities:
Property, plant and equipment	(31,773)	(40,373)
Intangible assets	(11,961)	(43,487)
Right-of-use assets, net	(38,932)	(44,722)
Other	(5,820)	(6,609)
Deferred tax liabilities	(88,486)	(135,191)
Net deferred tax liability before valuation allowance	43,266	(5,503)
Valuation allowance	(20,854)	(20,517)
Net deferred tax assets	$ 22,412
Net deferred tax liability		$ (26,020)