REVENUE, Disclosure of Impact of Adoption on Balance Sheet and Consolidated Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Assets [Abstract]
Unbilled receivables	$ 16,553		$ 16,553		$ 0
Inventories	114,434		114,434		107,719
Liabilities [Abstract]
Other current liabilities	3,836		3,836		6,204
Equity [Abstract]
Retained earnings	165,518		165,518		147,807
Statement of Operations [Abstract]
Net sales	146,489	$ 126,386	405,451	$ 371,671
Cost of sales	117,282	98,686	326,096	291,481
Operating income	10,499	6,794	21,603	16,415
(Benefit from) provision for income taxes	(2,201)	60	523	2,329
Net earnings	11,352	$ 5,024	16,684	$ 8,890
ASU 2014-09 [Member]
Assets [Abstract]
Unbilled receivables					14,536
Inventories					96,675
Liabilities [Abstract]
Other current liabilities					6,247
Equity [Abstract]
Retained earnings					151,256
Balances Without Adoption of ASC 606 [Member] | ASU 2014-09 [Member]
Assets [Abstract]
Unbilled receivables	0		0
Inventories	126,737		126,737
Liabilities [Abstract]
Other current liabilities	3,715		3,715
Equity [Abstract]
Retained earnings	161,389		161,389
Statement of Operations [Abstract]
Net sales	145,523		403,434
Cost of sales	116,312		324,837
Operating income	10,503		20,845
(Benefit from) provision for income taxes	(2,163)		445
Net earnings	11,318		16,004
Effect of Change Higher/(Lower) [Member] | ASU 2014-09 [Member]
Assets [Abstract]
Unbilled receivables	16,553		16,553		14,536
Inventories	(12,303)		(12,303)		(11,044)
Liabilities [Abstract]
Other current liabilities	121		121		43
Equity [Abstract]
Retained earnings	4,129		4,129		$ 3,449
Statement of Operations [Abstract]
Net sales	966		2,017
Cost of sales	970		1,259
Operating income	(4)		758
(Benefit from) provision for income taxes	(38)		78
Net earnings	$ 34		$ 680