SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Enterprise Wide Disclosures and Foreign Currency Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Enterprise-Wide Disclosures
Property and equipment, net	$ 10,178	$ 10,176
Other assets	3,906	4,122
Foreign Currency Transactions
Foreign currency translation adjustment	233	101
Foreign currency translation adjustment	(132)	(57)
Net foreign currency transaction gains (losses)	(170)	(192)
Net Sales	$ 113,370	$ 112,335
Maximum
Enterprise-Wide Disclosures
Percentage of sales (as a percent)	10.00%	10.00%
ASU 2016-02 | Restatement Adjustment | Minimum
Recently Issued and Adopted Accounting Pronouncements
Lease assets			$ 5,500
Lease liabilities			5,500
ASU 2016-02 | Restatement Adjustment | Maximum
Recently Issued and Adopted Accounting Pronouncements
Lease assets			6,500
Lease liabilities			$ 6,500
United States
Enterprise-Wide Disclosures
Property and equipment, net	$ 8,687	$ 8,713
Other assets	3,898	4,114
Mexico
Enterprise-Wide Disclosures
Property and equipment, net	821	1,003
Other assets	8	8
China
Enterprise-Wide Disclosures
Property and equipment, net	$ 670	$ 460
Export sales | Domestic
Enterprise-Wide Disclosures
Percentage of sales (as a percent)	4.80%	4.50%
Aerospace and Defense
Foreign Currency Transactions
Net Sales	$ 18,314	$ 15,683
Medical
Foreign Currency Transactions
Net Sales	45,082	51,449
Industrial
Foreign Currency Transactions
Net Sales	$ 49,974	$ 45,203