Segment Information (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 745.2	$ 695.6
United States
Disaggregation of Revenue [Line Items]
Net sales	519.8	472.1
Europe
Disaggregation of Revenue [Line Items]
Net sales	120.8	127.0
All other
Disaggregation of Revenue [Line Items]
Net sales	104.6	96.5
Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	662.6	621.9
Cost Type
Disaggregation of Revenue [Line Items]
Net sales	82.6	73.7
US Government
Disaggregation of Revenue [Line Items]
Net sales	169.9	159.5
Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	575.3	536.1
Instrumentation
Disaggregation of Revenue [Line Items]
Net sales	256.5	239.0
Instrumentation | United States
Disaggregation of Revenue [Line Items]
Net sales	211.1	191.0
Instrumentation | Europe
Disaggregation of Revenue [Line Items]
Net sales	33.6	39.4
Instrumentation | All other
Disaggregation of Revenue [Line Items]
Net sales	11.8	8.6
Instrumentation | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	251.0	234.1
Instrumentation | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	5.5	4.9
Instrumentation | US Government
Disaggregation of Revenue [Line Items]
Net sales	14.2	12.8
Instrumentation | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	242.3	226.2
Digital Imaging
Disaggregation of Revenue [Line Items]
Net sales	235.3	211.0
Digital Imaging | United States
Disaggregation of Revenue [Line Items]
Net sales	72.4	56.8
Digital Imaging | Europe
Disaggregation of Revenue [Line Items]
Net sales	70.3	67.0
Digital Imaging | All other
Disaggregation of Revenue [Line Items]
Net sales	92.6	87.2
Digital Imaging | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	213.3	191.2
Digital Imaging | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	22.0	19.8
Digital Imaging | US Government
Disaggregation of Revenue [Line Items]
Net sales	26.2	22.4
Digital Imaging | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	209.1	188.6
Aerospace and Defense Electronics
Disaggregation of Revenue [Line Items]
Net sales	180.4	173.6
Aerospace and Defense Electronics | United States
Disaggregation of Revenue [Line Items]
Net sales	165.1	154.1
Aerospace and Defense Electronics | Europe
Disaggregation of Revenue [Line Items]
Net sales	15.1	18.8
Aerospace and Defense Electronics | All other
Disaggregation of Revenue [Line Items]
Net sales	0.2	0.7
Aerospace and Defense Electronics | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	180.1	173.4
Aerospace and Defense Electronics | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	0.3	0.2
Aerospace and Defense Electronics | US Government
Disaggregation of Revenue [Line Items]
Net sales	68.0	65.3
Aerospace and Defense Electronics | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	112.4	108.3
Engineered Systems
Disaggregation of Revenue [Line Items]
Net sales	73.0	72.0
Engineered Systems | United States
Disaggregation of Revenue [Line Items]
Net sales	71.2	70.2
Engineered Systems | Europe
Disaggregation of Revenue [Line Items]
Net sales	1.8	1.8
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	18.2	23.2
Engineered Systems | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	54.8	48.8
Engineered Systems | US Government
Disaggregation of Revenue [Line Items]
Net sales	61.5	59.0
Engineered Systems | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	$ 11.5	$ 13.0