Revenue from Contracts with Customers - Schedule of Deferred Revenue and Customer Advances by Arrangement (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Change in Contract with Customer, Liability [Line Items]
Beginning balance, January 1	$ 24.8	$ 17.5
Additions to deferred revenue and customer advances	76.3	41.9
Amount of deferred revenue and customer advances recognized in income	(65.6)	(38.8)
Ending balance, March 31	$ 35.5	25.2
Electro Scientific Industries Inc [Member]
Change in Contract with Customer, Liability [Line Items]
Deferred revenue and customer advances assumed		$ 4.6