Business Acquisitions and Dispositions - Narrative (Details) - USD ($)		1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 02, 2018	Aug. 31, 2019	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Feb. 28, 2018
Business Acquisition [Line Items]
Goodwill			$ 1,811,800,000	$ 1,811,800,000	$ 1,784,400,000	$ 1,089,000,000.0
Acquisitions, net of cash acquired				70,800,000	1,118,000,000.0	184,100,000
Gain on disposition of business				$ 21,700,000	$ 0	0
Disposal by sale | Haefely Test, AG
Business Acquisition [Line Items]
Proceeds from Disposal of business		$ 38,100,000
Dispositions, tangible assets		32,300,000
Dispositions, goodwill		3,100,000
Dispositions, liabilities		12,200,000
Dispositions, translation adjustments recognized		$ 7,700,000
Term Loan Agreement | Line of Credit
Business Acquisition [Line Items]
Line of credit, maximum borrowing capacity	$ 500,000,000
Notes 2028 Term | Senior Notes
Business Acquisition [Line Items]
Senior notes, stated percentage	3.50%		3.50%	3.50%	3.50%		3.50%
Face amount	$ 450,000,000						$ 450,000,000
2019 Acquisitions
Business Acquisition [Line Items]
Goodwill			$ 29,400,000	$ 29,400,000
Cantega
Business Acquisition [Line Items]
Consideration transferred to acquire business			36,300,000
Intangible asset acquired			20,400,000	20,400,000
Goodwill			$ 14,200,000	14,200,000
Weighted average estimated useful life			12 years
CPI
Business Acquisition [Line Items]
Consideration transferred to acquire business			$ 28,000,000.0
Intangible asset acquired			12,800,000	12,800,000
Goodwill			$ 10,500,000	10,500,000
Weighted average estimated useful life			18 years
Other 2019 Acquisition
Business Acquisition [Line Items]
Consideration transferred to acquire business			$ 5,000,000.0
Goodwill			$ 4,700,000	4,700,000
Aclara
Business Acquisition [Line Items]
Consideration transferred to acquire business	1,100,000,000
Goodwill	708,700,000
Deductible goodwill	$ 159,900,000
Transaction costs					$ 12,800,000	$ 7,100,000
Contributed sales					611,100,000
Contributed operating income					29,600,000
Prior Immaterial Business Acquisitions
Business Acquisition [Line Items]
Deferred purchase price and net working capital settlements				$ 1,500,000	$ 1,700,000