Segment Information - Sales (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Revenue from External Customer [Line Items]
Net sales	$ 743.3	$ 782.0	$ 1,527.9	$ 1,527.2
Instrumentation
Revenue from External Customer [Line Items]
Net sales	263.1	264.1	548.2	520.6
Operating Segments | Instrumentation
Revenue from External Customer [Line Items]
Net sales	263.1	264.1	548.2	520.6
Operating Segments | Instrumentation | Marine Instrumentation
Revenue from External Customer [Line Items]
Net sales	109.9	111.4	219.2	216.6
Operating Segments | Instrumentation | Environmental Instrumentation
Revenue from External Customer [Line Items]
Net sales	94.3	87.4	203.6	173.8
Operating Segments | Instrumentation | Test and Measurement Instrumentation
Revenue from External Customer [Line Items]
Net sales	$ 58.9	$ 65.3	$ 125.4	$ 130.2