SEGMENT INFORMATION (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 595,393	$ 567,901	$ 1,763,213	$ 1,659,145
Operating income (expense)	97,047	92,414	263,621	219,838
Identifiable assets	3,276,071		3,276,071		$ 3,236,321
Commercial Industrial [Member]
Segment Reporting Information [Line Items]
Net sales	295,448	294,158	904,806	865,070
Operating income (expense)	44,786	46,702	135,747	120,874
Identifiable assets	1,402,217		1,402,217		1,444,097
Defense [Member]
Segment Reporting Information [Line Items]
Net sales	138,433	142,681	407,401	384,917
Operating income (expense)	33,615	33,575	91,984	65,800
Identifiable assets	1,005,091		1,005,091		1,044,776
Power [Member]
Segment Reporting Information [Line Items]
Net sales	162,176	132,102	456,383	412,667
Operating income (expense)	28,249	17,771	62,792	57,191
Identifiable assets	705,262		705,262		482,753
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating income (expense)	(9,603)	(5,634)	(26,902)	(24,027)
Identifiable assets	163,501		163,501		$ 264,695
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	$ (664)	$ (1,040)	$ (5,377)	$ (3,509)