SEGMENT INFORMATION (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net sales	$ 567,653	$ 532,766	$ 1,091,244	$ 1,036,273
Operating income (expense)	83,271	68,089	134,498	125,352
Identifiable assets	3,121,274		3,121,274		$ 3,037,781
Commercial Industrial [Member]
Segment Reporting Information [Line Items]
Net sales	291,856	290,428	570,912	565,633
Operating income (expense)	43,693	38,957	74,314	69,009
Identifiable assets	1,420,411		1,420,411		1,391,040
Defense [Member]
Segment Reporting Information [Line Items]
Net sales	127,399	114,877	242,236	220,607
Operating income (expense)	21,187	18,609	32,342	35,454
Identifiable assets	1,013,636		1,013,636		751,859
Power [Member]
Segment Reporting Information [Line Items]
Net sales	149,970	129,123	280,565	252,869
Operating income (expense)	24,870	16,114	41,410	30,742
Identifiable assets	517,053		517,053		516,321
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating income (expense)	(6,479)	(5,591)	(13,568)	(9,853)
Identifiable assets	170,174		170,174		$ 378,561
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	$ (1,572)	$ (1,662)	$ (2,469)	$ (2,836)