REVENUE RECOGNITION - Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) segment	Jun. 30, 2019 USD ($)
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Number of reportable segment | segment			1
Revenues	$ 86,661	$ 92,630	$ 179,043	$ 186,526
United States
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Revenues	47,311	62,645	103,680	121,957
Europe
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Revenues	29,012	29,390	62,145	63,561
Other
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Revenues	10,338	595	13,218	1,008
Vehicle
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Revenues	18,584	30,778	46,639	64,374
Industrial
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Revenues	28,223	32,194	61,574	63,505
Medical
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Revenues	24,261	12,219	38,812	24,629
Aerospace & Defense
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Revenues	10,516	12,143	21,658	23,397
Other
Reconciliation of disaggregated revenue to segment revenue as well as revenue by geographical regions
Revenues	$ 5,077	$ 5,296	$ 10,360	$ 10,621