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Restructuring and Related Charges (Details) $ in Thousands		3 Months Ended	12 Months Ended
Restructuring and Related Charges (Details) $ in Thousands	Oct. 29, 2018 segment	Sep. 30, 2020 USD ($) segment	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)
Restructuring Cost and Reserve [Line Items]
Number of reportable segments \| segment	3	2	2
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning of the period			$ 655	$ 710	$ 3,542
Restructuring charges related to two-segment realignment			12,135	12,993	10,422
Release of prior reserves			(98)	(541)	(663)
Write-off charges			(2,461)	0	0
Cash payments			(9,367)	(12,966)	(13,280)
Restructuring Reserve, Translation and Other Adjustment			8	(82)	26
Restructuring reserve, end of the period		$ 970	970	655	710
Post Memcor product line sale restructuring [Member]
Restructuring Reserve [Roll Forward]
Restructuring charges related to two-segment realignment			8,274	0	0
Two-segment realignment [Member]
Restructuring Reserve [Roll Forward]
Restructuring charges related to two-segment realignment			2,092	11,090	0
Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Restructuring charges related to two-segment realignment			1,867	$ 2,444	$ 11,085
Other Restructuring [Member] \| Two-segment realignment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost		1,000	1,000
Other Restructuring [Member] \| Minimum [Member] \| Post Memcor product line sale restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost		3,000	3,000
Other Restructuring [Member] \| Maximum [Member] \| Post Memcor product line sale restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost		$ 5,000	$ 5,000