Acquisitions - Summary of Purchase Price (Detail) - USD ($) $ in Millions		9 Months Ended
	Feb. 01, 2019	Sep. 30, 2019
Acquisition Date [Line Items]
Total purchase price, net of cash and cash equivalents acquired		$ 988.6
Electro Scientific Industries Inc [Member]
Acquisition Date [Line Items]
Cash paid for outstanding shares	$ 1,032.7
Settlement of share-based compensation awards	30.6
Total purchase price	1,063.3
Less: Cash and cash equivalents acquired	(44.1)
Total purchase price, net of cash and cash equivalents acquired	$ 1,019.2