Revenue from Contracts with Customers - Summary of Revenue from Contracts with Customers (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
Disaggregation of Revenue [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
Products [Member]
Disaggregation of Revenue [Line Items]
Net revenues									2,014.8	1,611.3	1,835.2
Services [Member]
Disaggregation of Revenue [Line Items]
Net revenues									315.2	288.5	239.9
Vacuum & Analysis [Member]
Disaggregation of Revenue [Line Items]
Net revenues									1,405.9	990.5	1,260.8
Vacuum & Analysis [Member] | Products [Member]
Disaggregation of Revenue [Line Items]
Net revenues									1,222.4	819.1	1,080.3
Vacuum & Analysis [Member] | Services [Member]
Disaggregation of Revenue [Line Items]
Net revenues									183.5	171.4	180.5
Light & Motion [Member]
Disaggregation of Revenue [Line Items]
Net revenues									689.6	725.6	814.3
Light & Motion [Member] | Products [Member]
Disaggregation of Revenue [Line Items]
Net revenues									621.9	663.7	754.9
Light & Motion [Member] | Services [Member]
Disaggregation of Revenue [Line Items]
Net revenues									67.7	61.9	$ 59.4
Equipment & Solutions [Member]
Disaggregation of Revenue [Line Items]
Net revenues									234.5	183.7
Equipment & Solutions [Member] | Products [Member]
Disaggregation of Revenue [Line Items]
Net revenues									170.5	128.5
Equipment & Solutions [Member] | Services [Member]
Disaggregation of Revenue [Line Items]
Net revenues									$ 64.0	$ 55.2