Business Segment, Geographic Area, Product/Service Offerings and Significant Customer Information - Net Revenues by Reportable Segment (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net revenues	$ 660.2	$ 589.8	$ 544.3	$ 535.7	$ 499.7	$ 462.5	$ 474.1	$ 463.6	$ 2,330.0	$ 1,899.8	$ 2,075.1
Vacuum & Analysis [Member]
Segment Reporting Information [Line Items]
Net revenues									1,405.9	990.5	1,260.8
Light & Motion [Member]
Segment Reporting Information [Line Items]
Net revenues									689.6	725.6	$ 814.3
Equipment & Solutions [Member]
Segment Reporting Information [Line Items]
Net revenues									$ 234.5	$ 183.7