Acquisition - Summary of Estimated Fair Value of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Millions		12 Months Ended
	Feb. 01, 2019	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2018
Acquisition Date [Line Items]
Goodwill		$ 1,058.5	$ 1,066.4	$ 587.0
Total purchase price, net of cash and cash equivalents acquired		$ 988.6
Electro Scientific Industries Inc [Member]
Acquisition Date [Line Items]
Current assets (excluding inventory)	$ 208.0
Inventory	81.7
Intangible assets	316.2
Goodwill	474.0
Property, plant and equipment	65.5
Long-term assets	9.6
Total assets acquired	1,155.0
Current liabilities	51.5
Non-current deferred taxes	33.0
Other long-term liabilities	7.2
Total liabilities assumed	91.7
Fair value of assets acquired and liabilities assumed	1,063.3
Less: Cash and cash equivalents acquired	(44.1)
Total purchase price, net of cash and cash equivalents acquired	$ 1,019.2