Acquisitions - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Feb. 01, 2019
Business Acquisition [Line Items]
Business acquisition share price					$ 30.00
Stock-based compensation expense	$ 7.4	$ 7.4	$ 22.7	$ 42.1
Electro Scientific Industries Inc [Member]
Business Acquisition [Line Items]
Business acquisition share price					$ 30.00
Fair value write-up of acquired finished goods inventory	7.6		7.6
Incremental costs of sales charge				7.6
Fair value excluding write-up of acquired property, plant and equipment	$ 39.3		$ 39.3
Compensation expense				2.7
Stock-based compensation expense				$ 14.0