Business Segments (Details) $ in Thousands		3 Months Ended						9 Months Ended
	Oct. 29, 2018 segment	Jun. 30, 2021 USD ($) segment	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jun. 30, 2021 USD ($) segment	Jun. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	3	2						2
Segment Reporting Information [Line Items]
Revenue from product sales and services		$ 369,681			$ 347,827			$ 1,038,438	$ 1,045,595
Operating profit (loss)		28,310			33,066			60,722	123,913
Interest expense		(11,224)			(10,485)			(28,292)	(37,320)
Income (loss) before income taxes		17,086			22,581			32,430	86,593
Income tax (expense) benefit		(3,887)			(740)			(7,672)	(3,336)
Net income		13,199	$ 5,082	$ 6,477	21,841	$ 7,910	$ 53,506	24,758	83,257
Depreciation and amortization								83,707	80,056
Capital expenditures								54,147	65,924
Assets		1,843,158						1,843,158		$ 1,844,458
Goodwill		409,756						409,756		397,205
Integrated Solutions and Services
Segment Reporting Information [Line Items]
Revenue from product sales and services		239,687			228,711			678,538	694,734
Applied Product Technologies
Segment Reporting Information [Line Items]
Revenue from product sales and services		129,994			119,116			359,900	350,861
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue from product sales and services		25,167			18,837			71,054	61,646
Intersegment Eliminations | Integrated Solutions and Services
Segment Reporting Information [Line Items]
Revenue from product sales and services		5,727			1,603			11,832	8,204
Intersegment Eliminations | Applied Product Technologies
Segment Reporting Information [Line Items]
Revenue from product sales and services		19,440			17,234			59,222	53,442
Operating Segments
Segment Reporting Information [Line Items]
Total revenue		394,848			366,664			1,109,492	1,107,241
Operating Segments | Integrated Solutions and Services
Segment Reporting Information [Line Items]
Total revenue		245,414			230,314			690,370	702,938
Revenue from product sales and services		239,687			228,711			678,538
Operating profit (loss)		37,793			32,608			94,934	102,457
Assets		862,288						862,288		835,307
Goodwill		234,768						234,768		224,381
Operating Segments | Applied Product Technologies
Segment Reporting Information [Line Items]
Total revenue		149,434			136,350			419,122	404,303
Revenue from product sales and services		129,994			119,116			359,900
Operating profit (loss)		22,735			23,588			54,218	110,480
Assets		611,785						611,785		598,701
Goodwill		174,988						174,988		172,824
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Operating profit (loss)		(32,218)			$ (23,130)			(88,430)	$ (89,024)
Assets		$ 369,085						$ 369,085		$ 410,450