Debt - Narrative (Details)				9 Months Ended	12 Months Ended
	Feb. 19, 2021 USD ($)	Feb. 18, 2021	Apr. 10, 2020 USD ($)	Jun. 30, 2021 USD ($) lender invoice	Sep. 30, 2020 USD ($)	Dec. 17, 2018 USD ($)	Aug. 08, 2018 USD ($)
Line of Credit Facility [Line Items]
Number of customer invoices factored | invoice				1
Foreign subsidiary borrowings
Line of Credit Facility [Line Items]
Receivables pledged as collateral				$ 1,547,000	$ 1,859,000
Remaining debt balance				$ 7,101,000	$ 5,759,000
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				4.20%
First Loan
Line of Credit Facility [Line Items]
Debt instrument, number of lenders | lender				2
Face amount				$ 717,000
Debt instrument, term				6 years 6 months
Debt instrument, decrease, forgiveness				$ 287,000
Second Loan
Line of Credit Facility [Line Items]
Face amount				$ 303,000
Debt instrument, term				5 years
Revolving credit agreement
Line of Credit Facility [Line Items]
Percentage of stock pledged on credit agreement	66.67%
Revolving credit agreement | Credit Agreement
Line of Credit Facility [Line Items]
Fixed charge coverage ratio				1.1
Percent availability under revolving commitment		12.50%		10.00%	12.50%
Debt instrument, covenant combined commitment percentage				10.00%
Debt instrument, covenant combined borrowing base, percentage				10.00%
Debt instrument, covenant combined borrowing base, amount				$ 2,000,000
Receivables pledged as collateral				28,628,000	$ 26,964,000
Revolving credit agreement | Credit Agreement | Revolving credit agreement
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 28,000,000			35,000,000	35,000,000
Accordion feature, increase limit	10,000,000
Remaining borrowing capacity				$ 17,543,000	$ 13,284,000
Weighted average interest rate, revolving credit facility				1.84%
Commitment fee percentage				0.25%	0.25%
Debt issuance costs incurred				$ 45,000
Remaining unamortized amount				86,000
Revolving line of credit, accumulated amortization of debt issuance costs				$ 10,000	$ 205,000
Revolving credit agreement | Credit Agreement | Revolving credit agreement | LIBOR
Line of Credit Facility [Line Items]
Basis spread on LIBOR				1.75%
Revolving credit agreement | 2018 Credit Agreement | Revolving credit agreement
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity							$ 30,000,000
Weighted average interest rate, revolving credit facility					1.70%
Revolving credit agreement | 2018 Credit Agreement | Revolving credit agreement | LIBOR
Line of Credit Facility [Line Items]
Basis spread on LIBOR					1.50%
Revolving credit agreement | Fifth Amendment to Credit Agreement and First Amendment to Export Credit Agreement | Revolving credit agreement
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity	35,000,000
Revolving credit agreement | Export Credit Facility | Revolving credit agreement
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 7,000,000					$ 5,000,000
Weighted average interest rate, revolving credit facility				1.30%	1.20%
Revolving credit agreement | Export Credit Facility | Revolving credit agreement | LIBOR
Line of Credit Facility [Line Items]
Basis spread on LIBOR				1.25%	1.00%
Unsecured Promissory Note | PPP Loan
Line of Credit Facility [Line Items]
Face amount			$ 5,025,000
Debt instrument, term			2 years
Interest rate			0.98%
Deferral term			6 months
Unsecured Promissory Note | PPP Loan | JPMorgan Chase Bank, N.A.
Line of Credit Facility [Line Items]
Repayment debt					$ 261,000
Remaining debt balance				$ 4,764,000	$ 4,764,000