Segment Information (Sales) (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Revenue from External Customer [Line Items]
Net sales	$ 566.1	$ 530.5
Operating Segments | Instrumentation
Revenue from External Customer [Line Items]
Net sales	232.8	223.7
Operating Segments | Instrumentation | Marine Instrumentation
Revenue from External Customer [Line Items]
Net sales	109.5	112.9
Operating Segments | Instrumentation | Environmental Instrumentation
Revenue from External Customer [Line Items]
Net sales	75.5	68.7
Operating Segments | Instrumentation | Test and Measurement Instrumentation
Revenue from External Customer [Line Items]
Net sales	47.8	42.1
Operating Segments | Engineered Systems
Revenue from External Customer [Line Items]
Net sales	$ 67.6	$ 64.3