REVENUE DISAGGREGATION OF REVENUE (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Net sales	$ 571,614	$ 614,880	$ 1,722,892	$ 1,832,190
Defense [Member]
Disaggregation of Revenue [Line Items]
Net sales	308,030	276,403	892,482	787,709
Commercial [Member]
Disaggregation of Revenue [Line Items]
Net sales	263,584	338,477	830,410	1,044,481
Defense Aerospace [Member] | Defense [Member]
Disaggregation of Revenue [Line Items]
Net sales	121,987	110,742	333,120	293,955
Defense Ground [Member] | Defense [Member]
Disaggregation of Revenue [Line Items]
Net sales	20,519	22,231	63,205	69,383
Naval [Member] | Defense [Member]
Disaggregation of Revenue [Line Items]
Net sales	165,524	143,430	496,157	424,371
Commercial Aerospace [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Net sales	70,943	109,015	242,708	320,237
Power Generation [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Net sales	80,509	88,543	241,059	278,194
General Industrial [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Net sales	$ 112,132	$ 140,919	$ 346,643	$ 446,050
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales, Net, Percent	50.00%	47.00%	52.00%	48.00%
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Net Sales, Net, Percent	50.00%	53.00%	48.00%	52.00%