ACQUISITIONS Narrative (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Apr. 04, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Purchase consideration, net of cash acquired				$ 236,091	$ 2,504
Sotera
Business Acquisition [Line Items]
Purchase consideration, net of cash acquired	$ 236,100			236,091
Goodwill, expected to be tax deductible	103,500
Other intangible assets acquired	$ 23,450
Acquisition related costs incurred				4,300
Business Combination, Integration Related Costs		$ 2,400		$ 12,600
Milestone [Member]
Business Acquisition [Line Items]
Equity issued in a business acquisition (in shares)			129,530
Equity issued related to Acquisitions			$ 1,000
Geospacial Intelligence Collection Business [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred			$ 3,900