Property, Plant and Equipment - Net - Summary of Property, Plant and Equipment - Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Property Plant And Equipment [Abstract]
Land	$ 4,829	$ 3,350
Buildings and improvements	124,404	110,300
Manufacturing equipment	600,144	540,536
Computer equipment	30,016	28,198
Furniture and fixtures	7,016	6,867
Vehicles	1,063	941
Property Plant and Equipment Excluding Construction in Progress Gross	767,472	690,192
Construction in progress	91,536	140,566
Property and Equipment, Gross	859,008	830,758
Accumulated depreciation	(351,810)	(312,845)
Total property and equipment – net	$ 507,198	$ 517,913