Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Sep. 30, 2019
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 78,127	$ 75,223
Work in progress	16,712	14,741
Finished goods and products held for resale	64,184	58,223
Costs of unbilled projects	3,655	2,347
Reserves for excess and obsolete	(13,894)	(13,370)
Inventory, Net	$ 148,784	$ 137,164