Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 04, 2021	Mar. 29, 2020
Disaggregation of Revenue [Line Items]
Net sales	$ 805.7	$ 784.6
United States
Disaggregation of Revenue [Line Items]
Net sales	523.8	523.8
Europe
Disaggregation of Revenue [Line Items]
Net sales	156.5	147.9
All other
Disaggregation of Revenue [Line Items]
Net sales	125.4	112.9
Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	725.0	701.3
Cost Type
Disaggregation of Revenue [Line Items]
Net sales	80.7	83.3
United States Government
Disaggregation of Revenue [Line Items]
Net sales	207.6	212.9
Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	598.1	571.7
Instrumentation
Disaggregation of Revenue [Line Items]
Net sales	286.5	285.1
Instrumentation | United States
Disaggregation of Revenue [Line Items]
Net sales	213.4	217.8
Instrumentation | Europe
Disaggregation of Revenue [Line Items]
Net sales	58.6	54.9
Instrumentation | All other
Disaggregation of Revenue [Line Items]
Net sales	14.5	12.4
Instrumentation | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	282.8	281.5
Instrumentation | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	3.7	3.6
Instrumentation | United States Government
Disaggregation of Revenue [Line Items]
Net sales	22.6	41.5
Instrumentation | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	263.9	243.6
Digital Imaging
Disaggregation of Revenue [Line Items]
Net sales	263.3	246.7
Digital Imaging | United States
Disaggregation of Revenue [Line Items]
Net sales	80.2	77.6
Digital Imaging | Europe
Disaggregation of Revenue [Line Items]
Net sales	72.2	68.8
Digital Imaging | All other
Disaggregation of Revenue [Line Items]
Net sales	110.9	100.3
Digital Imaging | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	240.1	213.4
Digital Imaging | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	23.2	33.3
Digital Imaging | United States Government
Disaggregation of Revenue [Line Items]
Net sales	32.1	29.3
Digital Imaging | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	231.2	217.4
Aerospace and Defense Electronics
Disaggregation of Revenue [Line Items]
Net sales	151.2	156.3
Aerospace and Defense Electronics | United States
Disaggregation of Revenue [Line Items]
Net sales	125.5	131.9
Aerospace and Defense Electronics | Europe
Disaggregation of Revenue [Line Items]
Net sales	25.7	24.2
Aerospace and Defense Electronics | All other
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.2
Aerospace and Defense Electronics | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	151.1	156.1
Aerospace and Defense Electronics | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	0.1	0.2
Aerospace and Defense Electronics | United States Government
Disaggregation of Revenue [Line Items]
Net sales	53.7	53.8
Aerospace and Defense Electronics | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	97.5	102.5
Engineered Systems
Disaggregation of Revenue [Line Items]
Net sales	104.7	96.5
Engineered Systems | United States
Disaggregation of Revenue [Line Items]
Net sales	104.7	96.5
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	51.0	50.3
Engineered Systems | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	53.7	46.2
Engineered Systems | United States Government
Disaggregation of Revenue [Line Items]
Net sales	99.2	88.3
Engineered Systems | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	$ 5.5	$ 8.2