REVENUE DISAGGREGATION OF REVENUE (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 638,996	$ 620,298	$ 1,217,310	$ 1,167,820
Defense [Member]
Disaggregation of Revenue [Line Items]
Net sales	280,673	252,778	511,305	457,939
Commercial [Member]
Disaggregation of Revenue [Line Items]
Net sales	358,323	367,520	706,005	709,881
Defense Aerospace [Member] | Defense [Member]
Disaggregation of Revenue [Line Items]
Net sales	104,426	99,654	183,213	178,808
Defense Ground [Member] | Defense [Member]
Disaggregation of Revenue [Line Items]
Net sales	26,394	20,777	47,151	43,296
Naval [Member] | Defense [Member]
Disaggregation of Revenue [Line Items]
Net sales	149,853	132,347	280,941	235,835
Commercial Aerospace [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Net sales	108,000	104,617	211,222	204,021
Power Generation [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Net sales	93,171	102,316	189,652	200,635
General Industrial [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Net sales	$ 157,152	$ 160,587	$ 305,131	$ 305,225
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales, Net, Percent	48.00%	45.00%	48.00%	45.00%
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales, Net, Percent	52.00%	55.00%	52.00%	55.00%