SEGMENT INFORMATION (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 620,298	$ 567,653	$ 1,167,820	$ 1,091,244
Operating income (expense)	102,076	79,732	166,574	127,424
Identifiable assets	3,230,188		3,230,188		$ 3,236,321
Commercial Industrial [Member]
Segment Reporting Information [Line Items]
Net sales	312,605	291,856	609,358	570,912
Operating income (expense)	51,736	43,620	90,961	74,172
Identifiable assets	1,425,220		1,425,220		1,444,097
Defense [Member]
Segment Reporting Information [Line Items]
Net sales	148,085	127,399	268,968	242,236
Operating income (expense)	38,641	21,128	58,369	32,225
Identifiable assets	988,651		988,651		1,044,776
Power [Member]
Segment Reporting Information [Line Items]
Net sales	162,049	149,970	294,207	280,565
Operating income (expense)	19,201	23,875	34,543	39,420
Identifiable assets	709,066		709,066		482,753
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating income (expense)	(7,502)	(8,891)	(17,299)	(18,393)
Identifiable assets	107,251		107,251		$ 264,695
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	$ (2,441)	$ (1,572)	$ (4,713)	$ (2,469)