Acquisitions and Dispositions - Allocation of Acquired Intangible Assets and Liabilities Related Estimates of Useful Lives (Detail) - USD ($)
$ in Thousands

Acquisitions and Dispositions - Allocation of Acquired Intangible Assets and Liabilities Related Estimates of Useful Lives (Detail) - USD ($) $ in Thousands			1 Months Ended	12 Months Ended
	Apr. 29, 2016	Mar. 17, 2015	Mar. 17, 2015	Dec. 31, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 404,506
Minimum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life of finite-lived intangible assets				1 year
Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life of finite-lived intangible assets				18 years
Newport [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price					$ 404,506
Precisive, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price		$ 5,110
Order Backlog [Member] \| Newport [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 12,100
Estimated useful life of finite-lived intangible assets	1 year
Order Backlog [Member] \| Precisive, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price		50
Estimated useful life of finite-lived intangible assets			18 months
Customer Relationships [Member] \| Newport [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 247,793				$ 247,793
Customer Relationships [Member] \| Newport [Member] \| Minimum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life of finite-lived intangible assets	6 years
Customer Relationships [Member] \| Newport [Member] \| Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life of finite-lived intangible assets	18 years
Customer Relationships [Member] \| Precisive, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price		1,430
Estimated useful life of finite-lived intangible assets			8 years
Trademarks and Trade Names [Member] \| Newport [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 55,900
Estimated useful life of finite-lived intangible assets	Indefinite
Developed Technology [Member] \| Newport [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 75,386
Developed Technology [Member] \| Newport [Member] \| Minimum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life of finite-lived intangible assets	4 years
Developed Technology [Member] \| Newport [Member] \| Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life of finite-lived intangible assets	8 years
Developed Technology [Member] \| Precisive, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price		820
Estimated useful life of finite-lived intangible assets			10 years
In-process Research and Development [Member] \| Newport [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 6,899
Estimated useful life of finite-lived intangible assets	Undefined
Leasehold Interest Favorable [Member] \| Newport [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 6,428
Leasehold Interest Favorable [Member] \| Newport [Member] \| Minimum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life of finite-lived intangible assets	4 years
Leasehold Interest Favorable [Member] \| Newport [Member] \| Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life of finite-lived intangible assets	5 years
Leasehold Interest Unfavorable [Member] \| Newport [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 4,302
Exclusive Patent License [Member] \| Precisive, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price		2,600
Estimated useful life of finite-lived intangible assets			10 years
Trade names [Member] \| Precisive, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price		$ 210
Estimated useful life of finite-lived intangible assets			10 years