REVENUE RECOGNITION - Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) segment	Sep. 30, 2018 USD ($)
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Number of reportable segment | segment			1
Disaggregation of revenue	$ 96,633	$ 80,092	$ 283,159	$ 236,649
United States
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Disaggregation of revenue	64,739	49,375	186,697	140,031
Europe
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Disaggregation of revenue	31,448	29,975	95,010	94,754
Asia
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Disaggregation of revenue	446	742	1,452	1,864
Vehicle
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Disaggregation of revenue	33,001	31,717	97,375	95,071
Industrial
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Disaggregation of revenue	30,572	24,668	94,076	76,633
Medical
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Disaggregation of revenue	14,550	10,732	39,180	31,214
Aerospace & Defense
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Disaggregation of revenue	12,621	10,332	36,018	26,701
Other
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Disaggregation of revenue	$ 5,889	$ 2,643	$ 16,510	$ 7,030