Business Segment, Geographic Area, Product/Service Offerings and Significant Customer Information - Segment Assets by Reportable Segment (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Accounts receivable	$ 392.7	$ 341.1
Inventory	501.4	462.1
Total segment assets	894.1	803.2
Operating Segments [Member] | Vacuum & Analysis [Member]
Segment Reporting Information [Line Items]
Accounts receivable	229.1	185.9
Inventory	273.3	224.8
Total segment assets	502.4	410.7
Operating Segments [Member] | Light & Motion [Member]
Segment Reporting Information [Line Items]
Accounts receivable	122.6	147.2
Inventory	166.1	163.7
Total segment assets	288.7	310.9
Operating Segments [Member] | Equipment & Solutions [Member]
Segment Reporting Information [Line Items]
Accounts receivable	51.7	40.1
Inventory	63.7	73.5
Total segment assets	115.4	113.6
Corporate, Eliminations & Other [Member]
Segment Reporting Information [Line Items]
Accounts receivable	(10.7)	(32.1)
Inventory	(1.7)	0.1
Total segment assets	$ (12.4)	$ (32.0)