Segment Information - Detailed Segment Data (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019
Segment Reporting Information [Line Items]
Sales	$ 1,902.3	$ 1,860.0	$ 5,187.0	$ 5,317.6
Operating profit	310.4	242.1	621.1	708.9
Gain from combination of business	0.0	41.2	0.0	41.2
Interest expense, net	(43.9)	(47.0)	(130.7)	(116.7)
Other non-operating income (expense), net	(1.4)	(1.2)	(0.7)	(1.6)
Earnings from continuing operations before income taxes	265.1	235.1	489.7	631.8
Operating Segments | Professional Instrumentation
Segment Reporting Information [Line Items]
Sales	1,155.7	1,145.6	3,297.6	3,288.9
Operating profit	168.7	126.2	448.8	398.8
Operating Segments | Industrial Technologies
Segment Reporting Information [Line Items]
Sales	746.6	714.4	1,889.4	2,028.7
Operating profit	165.5	138.5	246.6	382.3
Other
Segment Reporting Information [Line Items]
Operating profit	$ (23.8)	$ (22.6)	$ (74.3)	$ (72.2)