Debt - Narrative (Details)					1 Months Ended		9 Months Ended	12 Months Ended
	Apr. 10, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 20, 2019 USD ($)	Aug. 08, 2018 USD ($)	Sep. 30, 2019 USD ($) tranche repayment	Dec. 31, 2018 USD ($)	Jun. 30, 2020 USD ($) invoice	Sep. 30, 2019 USD ($)	Mar. 31, 2020 USD ($)	Dec. 17, 2018 USD ($)
Line of Credit Facility [Line Items]
Short-term debt arrangement		$ 15,542,000			$ 15,542,000		$ 11,302,000	$ 15,542,000
Number of customer invoices factored | invoice							1
Foreign subsidiary borrowings
Line of Credit Facility [Line Items]
Receivables pledged as collateral		672,000			$ 672,000		$ 1,322,000	672,000
Long-term debt, number of tranches with modified repayment schedule | tranche					1
Debt instrument, number of repayments reduced | repayment					2
Debt instrument, repayment reduction per payment, amount					$ 96,000
Debt instrument, loan extension period					6 months
Remaining debt balance		$ 6,592,000			$ 6,592,000		$ 5,159,000	$ 6,592,000
Foreign subsidiary borrowings | Euribor | Minimum
Line of Credit Facility [Line Items]
Euribor variable interest rates							1.00%
Foreign subsidiary borrowings | Euribor | Maximum
Line of Credit Facility [Line Items]
Euribor variable interest rates							4.24%
2018 Credit Agreement | Revolving credit agreement
Line of Credit Facility [Line Items]
Fixed charge coverage ratio				1.1
Percent availability under revolving commitment				12.50%
Percentage of stock pledged on credit agreement			66.67%
2018 Credit Agreement | Revolving credit agreement | Revolving credit agreement
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity				$ 30,000,000
Accordion feature, increase limit				$ 10,000,000
Weighted average interest rate, revolving credit facility		3.60%			3.60%		1.70%	3.60%
Commitment fee percentage							0.25%
Debt issuance costs incurred							$ 212,000
Revolving line of credit, accumulated amortization of debt issuance costs		$ 106,000			$ 106,000		$ 180,000	$ 106,000
2018 Credit Agreement | Revolving credit agreement | Revolving credit agreement | LIBOR
Line of Credit Facility [Line Items]
Basis spread on LIBOR							1.50%
Export Credit Facility | Revolving credit agreement | Revolving credit agreement
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity										$ 5,000,000
Accordion feature, increase limit										$ 35,000,000
Weighted average interest rate, revolving credit facility		3.40%			3.40%		1.20%	3.40%
Export Credit Facility | Revolving credit agreement | Revolving credit agreement | LIBOR
Line of Credit Facility [Line Items]
Basis spread on LIBOR							1.00%	1.25%
Third Amendment to Credit Agreement | Revolving credit agreement
Line of Credit Facility [Line Items]
Coverage ratio threshold for three or more business days in consecutive thirty day period			12.50%
Fourth Amendment to Credit Agreement | Revolving credit agreement
Line of Credit Facility [Line Items]
Fixed charge coverage ratio				1.1
Percent availability under revolving commitment			10.00%
Coverage ratio threshold for three or more business days in consecutive thirty day period		10.00%	10.00%
Line of credit facility, benchmark of collateral threshold			$ 20,000,000
Receivables pledged as collateral		$ 24,000,000			$ 24,000,000		$ 25,603,000	$ 24,000,000
Fourth Amendment to Credit Agreement | Revolving credit agreement | Revolving credit agreement
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity		35,000,000			35,000,000			35,000,000	$ 35,000,000
Line of credit facility, covenant terms, floor			2,000,000
Line of credit facility, benchmark of collateral threshold			$ 20,000,000
Line of credit facility, total commitment springs		2,400,000			2,400,000		2,560,000	2,400,000
Remaining borrowing capacity		7,709,000			7,709,000		13,492,000	7,709,000
Short Term Debt Arrangement for Working Capital Purposes
Line of Credit Facility [Line Items]
Debt instrument, term						6 months
Short-term debt arrangement						$ 1,137,000
First And Second Amendment to 2018 Credit Agreement | Revolving credit agreement | Revolving credit agreement
Line of Credit Facility [Line Items]
Debt issuance costs incurred		$ 75,000			$ 75,000			$ 75,000
PPP Loan | Unsecured Promissory Note
Line of Credit Facility [Line Items]
Debt instrument, term	2 years
Face amount	$ 5,025,000
Interest rate	0.98%
Deferral term	6 months
JPMorgan Chase Bank, N.A. | PPP Loan | Unsecured Promissory Note
Line of Credit Facility [Line Items]
Repayment debt							261,000
Remaining debt balance							4,764,000
Long-term debt paid in 2021							2,382,000
Long-term debt paid in 2022							$ 2,382,000