Acquisitions - Allocation of Acquired Intangible Assets and Liabilities Related Estimates of Useful Lives (Detail) - Electro Scientific Industries Inc [Member] - USD ($) $ in Millions		12 Months Ended
	Feb. 01, 2019	Dec. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 316.2	$ 316.2
Completed Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price		274.0
Completed Technology [Member] | Lasers Products [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 255.7
Estimated useful life of finite-lived intangible assets	12 years
Completed Technology [Member] | Non Laser Products [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 18.3
Estimated useful life of finite-lived intangible assets	10 years
Trademarks and Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 14.4
Estimated useful life of finite-lived intangible assets	7 years
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 25.4	$ 25.4
Estimated useful life of finite-lived intangible assets	10 years
Backlog [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$ 2.4
Estimated useful life of finite-lived intangible assets	1 year