SEGMENT INFORMATION - Schedule of Long-lived Assets and Net Sales By Geography (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 750,946	$ 832,749	$ 679,788
Net sales	2,850,378	3,202,053	3,518,761
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	681,948	756,108	612,066
Net sales	2,501,481	2,817,844	3,150,143
Other Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	8,253	9,168	8,655
Net sales	80,380	92,361	94,064
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	53,300	55,907	52,498
Net sales	220,803	245,764	228,885
Asia-Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	7,445	11,566	6,569
Net sales	$ 47,714	$ 46,084	$ 45,669