Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands			1 Months Ended				12 Months Ended
	Nov. 28, 2018	Nov. 06, 2017	Jul. 31, 2018	Dec. 31, 2017	Nov. 30, 2017	Oct. 31, 2016	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Jul. 26, 2018
Finite-Lived Intangible Assets [Line Items]
Debt instrument, fee amount			$ 1,346
Line of credit facility, remaining borrowing capacity							$ 45,000	$ 45,000
Payments of Financing Costs							760
Repayments of debt		$ 104,936
Amortization of debt issuance costs and discounts							1,735	1,991	$ 2,498
Write off of deferred debt issuance cost			$ 2,581	$ 1,150		$ 1,844	1,795	0		$ 5,575
Prepayment of debt					$ 100,000
Foreign currency losses (gains) on intracompany loans							(8,216)	12,599	7,018
Research and development costs							$ 13,198	15,300	$ 15,877
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life							1 year
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life							26 years
Machinery and equipment | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Property, plant and equipment, useful life							3 years
Machinery and equipment | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Property, plant and equipment, useful life							20 years
Building and Building Improvements | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Property, plant and equipment, useful life							10 years
Building and Building Improvements | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Property, plant and equipment, useful life							40 years
December Refinancing [Member]
Finite-Lived Intangible Assets [Line Items]
Debt instrument, fee amount								2,131
Term Loan [Member] | First Lien Term Loan, due December 20, 2024
Finite-Lived Intangible Assets [Line Items]
Line of credit facility, remaining borrowing capacity											$ 150,000
Revolving Credit Facility
Finite-Lived Intangible Assets [Line Items]
Line of credit facility, remaining borrowing capacity							$ 125,000	125,000
Interest Rate Cap [Member]
Finite-Lived Intangible Assets [Line Items]
Derivative, Cost of Hedge Net of Cash Received	$ 2,235
Derivative, Term of Contract	3 years
Amortization							496	$ 621
Write off of deferred debt issuance cost							$ 1,118