Segment Information (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Net sales	$ 784.6	$ 745.2
United States
Disaggregation of Revenue [Line Items]
Net sales	523.8	519.8
Europe
Disaggregation of Revenue [Line Items]
Net sales	147.9	120.8
All other
Disaggregation of Revenue [Line Items]
Net sales	112.9	104.6
Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	701.3	648.5
Cost Type
Disaggregation of Revenue [Line Items]
Net sales	83.3	96.7
US Government
Disaggregation of Revenue [Line Items]
Net sales	212.9	169.9
Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	571.7	575.3
Instrumentation
Disaggregation of Revenue [Line Items]
Net sales	285.1	256.5
Instrumentation | United States
Disaggregation of Revenue [Line Items]
Net sales	217.8	211.1
Instrumentation | Europe
Disaggregation of Revenue [Line Items]
Net sales	54.9	33.6
Instrumentation | All other
Disaggregation of Revenue [Line Items]
Net sales	12.4	11.8
Instrumentation | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	281.5	251.0
Instrumentation | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	3.6	5.5
Instrumentation | US Government
Disaggregation of Revenue [Line Items]
Net sales	41.5	14.2
Instrumentation | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	243.6	242.3
Digital Imaging
Disaggregation of Revenue [Line Items]
Net sales	246.7	232.4
Digital Imaging | United States
Disaggregation of Revenue [Line Items]
Net sales	77.6	72.4
Digital Imaging | Europe
Disaggregation of Revenue [Line Items]
Net sales	68.8	67.4
Digital Imaging | All other
Disaggregation of Revenue [Line Items]
Net sales	100.3	92.6
Digital Imaging | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	213.4	199.2
Digital Imaging | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	33.3	33.2
Digital Imaging | US Government
Disaggregation of Revenue [Line Items]
Net sales	29.3	26.2
Digital Imaging | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	217.4	206.2
Aerospace and Defense Electronics
Disaggregation of Revenue [Line Items]
Net sales	156.3	166.6
Aerospace and Defense Electronics | United States
Disaggregation of Revenue [Line Items]
Net sales	131.9	146.6
Aerospace and Defense Electronics | Europe
Disaggregation of Revenue [Line Items]
Net sales	24.2	19.8
Aerospace and Defense Electronics | All other
Disaggregation of Revenue [Line Items]
Net sales	0.2	0.2
Aerospace and Defense Electronics | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	156.1	163.4
Aerospace and Defense Electronics | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	0.2	3.2
Aerospace and Defense Electronics | US Government
Disaggregation of Revenue [Line Items]
Net sales	53.8	49.5
Aerospace and Defense Electronics | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	102.5	117.1
Engineered Systems
Disaggregation of Revenue [Line Items]
Net sales	96.5	89.7
Engineered Systems | United States
Disaggregation of Revenue [Line Items]
Net sales	96.5	89.7
Engineered Systems | Europe
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0
Engineered Systems | All other
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0
Engineered Systems | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	50.3	34.9
Engineered Systems | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	46.2	54.8
Engineered Systems | US Government
Disaggregation of Revenue [Line Items]
Net sales	88.3	80.0
Engineered Systems | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	$ 8.2	$ 9.7