Segment Information (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Disaggregation of Revenue [Line Items]
Net sales	$ 725.3	$ 662.2	$ 2,153.4	$ 1,899.4
United States
Disaggregation of Revenue [Line Items]
Net sales	504.4		1,468.3
Europe
Disaggregation of Revenue [Line Items]
Net sales	128.0		394.5
All other
Disaggregation of Revenue [Line Items]
Net sales	92.9		290.6
Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	652.9		1,933.2
Cost Type
Disaggregation of Revenue [Line Items]
Net sales	72.4		220.2
US Government
Disaggregation of Revenue [Line Items]
Net sales	159.1		480.6
Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	566.2		1,672.8
Instrumentation
Disaggregation of Revenue [Line Items]
Net sales	256.2		757.8
Instrumentation | United States
Disaggregation of Revenue [Line Items]
Net sales	215.4		612.9
Instrumentation | Europe
Disaggregation of Revenue [Line Items]
Net sales	31.3		116.1
Instrumentation | All other
Disaggregation of Revenue [Line Items]
Net sales	9.5		28.8
Instrumentation | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	252.6		745.2
Instrumentation | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	3.6		12.6
Instrumentation | US Government
Disaggregation of Revenue [Line Items]
Net sales	15.4		44.0
Instrumentation | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	240.8		713.8
Digital Imaging
Disaggregation of Revenue [Line Items]
Net sales	223.0		659.3
Digital Imaging | United States
Disaggregation of Revenue [Line Items]
Net sales	62.6		178.8
Digital Imaging | Europe
Disaggregation of Revenue [Line Items]
Net sales	78.1		221.1
Digital Imaging | All other
Disaggregation of Revenue [Line Items]
Net sales	82.3		259.4
Digital Imaging | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	206.0		600.7
Digital Imaging | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	17.0		58.6
Digital Imaging | US Government
Disaggregation of Revenue [Line Items]
Net sales	23.9		68.9
Digital Imaging | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	199.1		590.4
Aerospace and Defense Electronics
Disaggregation of Revenue [Line Items]
Net sales	171.1		518.2
Aerospace and Defense Electronics | United States
Disaggregation of Revenue [Line Items]
Net sales	154.6		465.7
Aerospace and Defense Electronics | Europe
Disaggregation of Revenue [Line Items]
Net sales	15.4		50.1
Aerospace and Defense Electronics | All other
Disaggregation of Revenue [Line Items]
Net sales	1.1		2.4
Aerospace and Defense Electronics | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	170.0		516.4
Aerospace and Defense Electronics | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	1.1		1.8
Aerospace and Defense Electronics | US Government
Disaggregation of Revenue [Line Items]
Net sales	57.9		189.6
Aerospace and Defense Electronics | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	113.2		328.6
Engineered Systems
Disaggregation of Revenue [Line Items]
Net sales	75.0		218.1
Engineered Systems | United States
Disaggregation of Revenue [Line Items]
Net sales	71.8		210.9
Engineered Systems | Europe
Disaggregation of Revenue [Line Items]
Net sales	3.2		7.2
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	24.3		70.9
Engineered Systems | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	50.7		147.2
Engineered Systems | US Government
Disaggregation of Revenue [Line Items]
Net sales	61.9		178.1
Engineered Systems | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	$ 13.1		$ 40.0