Debt - Narrative (Details) - USD ($)		12 Months Ended
	Nov. 09, 2016	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Aug. 31, 2017	Aug. 04, 2017	Aug. 03, 2017	Nov. 30, 2016	Jan. 01, 2016	Jun. 26, 2015
Line Of Credit Facility [Line Items]
Outstanding borrowings			$ 7,941,000
Foreign debt borrowings, short-term borrowings			18,557,000	$ 12,751,000
Current maturities of long-term debt			7,560,000	18,258,000
Write off of debt issuance cost			323,000
Secured Debt | Forecast
Line Of Credit Facility [Line Items]
Reduction of term facility		$ 700,000
Foreign subsidiary borrowings
Line Of Credit Facility [Line Items]
Outstanding borrowings			8,346,000	9,540,000
Foreign debt borrowings, current			5,805,000	5,833,000
Foreign debt borrowings, short-term borrowings			2,618,000	3,262,000
Current maturities of long-term debt			1,340,000	2,014,000
Foreign debt borrowings, factoring payable, current			1,847,000	557,000
Receivables pledged as collateral, carrying value			$ 3,548,000	$ 1,156,000
Foreign subsidiary borrowings | Euro Interbank Offered Rate (Euribor) | Minimum
Line Of Credit Facility [Line Items]
Euribor variable interest rates			1.00%
Foreign subsidiary borrowings | Euro Interbank Offered Rate (Euribor) | Maximum
Line Of Credit Facility [Line Items]
Euribor variable interest rates			4.00%
2016 Amended and Restated Credit and Security Agreement
Line Of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 39,871,000
Non-U.S. subsidiaries stock percentage pledged			65.00%
Debt issuance costs, gross					$ 562,000			$ 562,000
Debt issuance costs, amount			$ 769,000
2016 Amended and Restated Credit and Security Agreement | Line of Credit
Line Of Credit Facility [Line Items]
Debt issuance cost related to revolving credit facility			707,000
Accumulated amortization of debt issuance costs, revolver			$ 282,000
2016 Amended and Restated Credit and Security Agreement | Secured Debt
Line Of Credit Facility [Line Items]
Issued amount of debt	4,871,000
Installment payment	$ 81,000
Installment payment starting date			Dec. 01, 2016
Debt issuance costs, gross			$ 61,000
Accumulated amortization of debt issuance costs, term loan			$ 14,000
2016 Amended and Restated Credit and Security Agreement | Secured Debt | London Interbank Offered Rate (LIBOR)
Line Of Credit Facility [Line Items]
Basis spread on LIBOR	4.25%
Weighted average interest rate			5.50%	3.80%
Fixed interest rate after effect of interest rate swap			5.80%	3.90%
2016 Amended and Restated Credit and Security Agreement | Revolving credit agreement
Line Of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 35,000,000
2016 Amended and Restated Credit and Security Agreement | Revolving credit agreement | Minimum
Line Of Credit Facility [Line Items]
Commitment fee	0.15%
2016 Amended and Restated Credit and Security Agreement | Revolving credit agreement | Maximum
Line Of Credit Facility [Line Items]
Commitment fee	0.375%
2016 Amended and Restated Credit and Security Agreement | Revolving credit agreement | London Interbank Offered Rate (LIBOR)
Line Of Credit Facility [Line Items]
Basis spread on LIBOR	3.75%
Weighted average interest rate			4.80%	3.90%
2015 Credit Agreement
Line Of Credit Facility [Line Items]
Debt issuance costs, gross										$ 724,000
Accumulated amortization of debt issuance costs, term loan								$ 194,000
2015 Credit Agreement | Secured Debt
Line Of Credit Facility [Line Items]
Issued amount of debt				$ 20,000,000
Installment payment				$ 714,000
Debt agreement term				5 years
2015 Credit Agreement | Revolving credit agreement
Line Of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity				$ 25,000,000					$ 20,000,000
Non-U.S. subsidiaries stock percentage pledged				65.00%
Debt agreement term				5 years
Credit facility accordion feature, increase amount				$ 15,000,000
Second Amendment Agreement | Line of Credit
Line Of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity						$ 30,000,000	$ 35,000,000