ACQUISITIONS (Narrative) (Detail) $ in Thousands						12 Months Ended
	Nov. 02, 2020	Apr. 20, 2020	Feb. 28, 2020	Dec. 31, 2019 USD ($)	Mar. 15, 2019	Dec. 31, 2020 USD ($) NumberAcquisitions	Dec. 31, 2019 USD ($) NumberAcquisitions	Dec. 31, 2018 USD ($)
Business Acquisition [Line Items]
Number of Businesses Acquired | NumberAcquisitions						3	2
Payments to Acquire Businesses, Gross						$ 487,944	$ 185,209	$ 210,167
Revenue of Acquiree since Acquisition Date, Actual						40,000	11,000
Earnings or Loss of Acquiree since Acquisition Date, Actual						(5,000)	0
Defense | Pacific Star Communications, Inc. (PacStar) [Member]
Business Acquisition [Line Items]
Effective date of acquisition	Nov. 02, 2020
Assets Acquired and Liabilities Assumed, Net						406,000
Defense | Integrated Air Defense System (IADS) [Member]
Business Acquisition [Line Items]
Effective date of acquisition		Apr. 20, 2020
Assets Acquired and Liabilities Assumed, Net						29,000
Defense | 901D Holdings, LLC (901D) [Member]
Business Acquisition [Line Items]
Effective date of acquisition				Dec. 31, 2019
Assets Acquired and Liabilities Assumed, Net				$ 135,000			135,000
Defense | Tactical Communications Group (TCG) [Member]
Business Acquisition [Line Items]
Effective date of acquisition					Mar. 15, 2019
Assets Acquired and Liabilities Assumed, Net				$ 50,000			$ 50,000
Commercial/Industrial | Dyna-Flo Valve Services Ltd. (Dyna-Flo) [Member]
Business Acquisition [Line Items]
Effective date of acquisition			Feb. 28, 2020
Assets Acquired and Liabilities Assumed, Net						$ 60,000