Debt - Narrative (Details) - USD ($)		3 Months Ended	12 Months Ended
	Nov. 09, 2016	Dec. 31, 2017	Sep. 30, 2017	Aug. 31, 2017	Aug. 04, 2017	Aug. 03, 2017	Nov. 30, 2016	Jun. 26, 2015
Line of Credit Facility [Line Items]
Revolving credit agreement		$ 18,755,000	$ 18,557,000
Foreign debt borrowings, long-term debt, current portion		8,084,000	7,560,000
Foreign subsidiary borrowings
Line of Credit Facility [Line Items]
Outstanding borrowings		8,492,000	8,346,000
Foreign debt borrowings, current		6,298,000	5,805,000
Revolving credit agreement		3,369,000	2,618,000
Foreign debt borrowings, long-term debt, current portion		1,222,000	1,340,000
Foreign debt borrowings, factoring payable, current		1,707,000	1,847,000
Receivables pledged as collateral, carrying value		$ 3,658,000	3,548,000
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%
Credit Facility
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 39,871,000
Debt issuance costs incurred				$ 562,000			$ 562,000
Debt issuance costs related to the term loan and revolving credit facility, gross		$ 768,000
Credit Facility | Line of Credit
Line of Credit Facility [Line Items]
Revolving line of credit, debt Issuance costs incurred, gross		707,000
Revolving line of credit, accumulated amortization of debt issuance costs		217,000
Credit Facility | Line of Credit | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on LIBOR	3.75%
Credit Facility | Term Loan
Line of Credit Facility [Line Items]
Issued amount of debt	$ 4,871,000
Installment payment	$ 81,000
Fixed interest rate after effect of interest rate swap	5.80%
Debt issuance costs incurred		61,000
Accumulated amortization of debt issuance costs		$ 19,000
Credit Facility | Term Loan | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on LIBOR		4.25%
Weighted average interest rate, revolving credit facility		5.60%
Credit Facility | Revolving credit agreement
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 35,000,000
Credit Facility | Revolving credit agreement | Minimum
Line of Credit Facility [Line Items]
Commitment fee percentage	0.15%
Credit Facility | Revolving credit agreement | Maximum
Line of Credit Facility [Line Items]
Commitment fee percentage	0.375%
Credit Facility | Revolving credit agreement | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Weighted average interest rate, revolving credit facility		5.40%
Second Amendment | Line of Credit
Line of Credit Facility [Line Items]
Revolving credit facility, maximum borrowing capacity					$ 30,000,000	$ 35,000,000
Second Amendment | Term Loan
Line of Credit Facility [Line Items]
Reduction of term facility					$ 700,000
2015 Credit Agreement
Line of Credit Facility [Line Items]
Debt issuance costs incurred								$ 724,000
Write off of deferred debt issuance cost due to debt modification			$ 323,000