SEGMENT INFORMATION (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018		Mar. 31, 2017		Dec. 31, 2017
Financial results of reportable segments
Sales		$ 79,882		$ 64,557
Depreciation and amortization		2,131		2,157
Segment (loss) income		2,635		(1,555)
Capital expenditures		1,417		480
Segment assets		321,134				$ 318,949
Reconciliation of segment income to consolidated income before income taxes
Income (loss) before income taxes		2,736		(1,850)
Operating segment
Financial results of reportable segments
Sales		79,882		64,557
Depreciation and amortization		1,745		1,908
Segment (loss) income		6,967		(384)
Capital expenditures		1,212		480
Segment assets		278,059	[1]	268,861	[1]	269,679
Reconciliation of segment income to consolidated income before income taxes
Unallocated corporate expense		(4,233)		(1,401)
Interest expense, net		2		(65)
Income (loss) before income taxes		2,736		(1,850)
Operating segment | MMS
Financial results of reportable segments
Sales		61,880		48,833
Depreciation and amortization		1,281		1,400
Segment (loss) income		2,866		(2,669)
Capital expenditures		692		336
Segment assets	[1]	229,300		223,349
Operating segment | ATA
Financial results of reportable segments
Sales		18,131		15,858
Depreciation and amortization		464		508
Segment (loss) income		4,101		2,285
Capital expenditures		520		144
Segment assets	[1]	48,759		45,512
Inter-Segment Eliminations
Financial results of reportable segments
Sales		(129)		$ (134)
Unallocated assets
Financial results of reportable segments
Segment assets		43,075				49,270
Reconciliation of segment income to consolidated income before income taxes
Cash		$ 39,500				$ 45,000

[1] Segment assets primarily consist of restricted cash, accounts receivable, inventories, prepaid and other assets, property, plant and equipment, and intangible assets. Unallocated assets primarily include, cash and cash equivalents, corporate property, plant and equipment, deferred income taxes, and other non-current assets.