Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Net sales	$ 743.3	$ 782.0	$ 1,527.9	$ 1,527.2
United States
Disaggregation of Revenue [Line Items]
Net sales	513.9	550.5	1,037.7	1,070.3
Europe
Disaggregation of Revenue [Line Items]
Net sales	122.7	129.2	270.6	250.0
All other
Disaggregation of Revenue [Line Items]
Net sales	106.7	102.3	219.6	206.9
Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	672.0	698.9	1,382.0	1,347.4
Cost Type
Disaggregation of Revenue [Line Items]
Net sales	71.3	83.1	145.9	179.8
US Government
Disaggregation of Revenue [Line Items]
Net sales	205.8	187.1	391.3	357.0
Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	537.5	594.9	1,136.6	1,170.2
Instrumentation
Disaggregation of Revenue [Line Items]
Net sales	263.1	264.1	548.2	520.6
Instrumentation | United States
Disaggregation of Revenue [Line Items]
Net sales	211.3	225.1	429.1	436.2
Instrumentation | Europe
Disaggregation of Revenue [Line Items]
Net sales	43.1	30.8	98.0	64.4
Instrumentation | All other
Disaggregation of Revenue [Line Items]
Net sales	8.7	8.2	21.1	20.0
Instrumentation | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	261.8	253.7	544.0	504.7
Instrumentation | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	1.3	10.4	4.2	15.9
Instrumentation | US Government
Disaggregation of Revenue [Line Items]
Net sales	21.4	18.6	35.5	32.8
Instrumentation | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	241.7	245.5	512.7	487.8
Digital Imaging
Disaggregation of Revenue [Line Items]
Net sales	237.6	248.4	484.3	480.8
Digital Imaging | United States
Disaggregation of Revenue [Line Items]
Net sales	78.0	80.3	155.6	152.7
Digital Imaging | Europe
Disaggregation of Revenue [Line Items]
Net sales	61.8	74.4	130.6	141.8
Digital Imaging | All other
Disaggregation of Revenue [Line Items]
Net sales	97.8	93.7	198.1	186.3
Digital Imaging | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	214.4	232.9	435.8	432.1
Digital Imaging | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	23.2	15.5	48.5	48.7
Digital Imaging | US Government
Disaggregation of Revenue [Line Items]
Net sales	30.1	26.2	59.4	52.4
Digital Imaging | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	207.5	222.2	424.9	428.4
Aerospace and Defense Electronics
Disaggregation of Revenue [Line Items]
Net sales	143.1	176.0	299.4	342.6
Aerospace and Defense Electronics | United States
Disaggregation of Revenue [Line Items]
Net sales	125.1	151.6	257.0	298.2
Aerospace and Defense Electronics | Europe
Disaggregation of Revenue [Line Items]
Net sales	17.8	24.0	42.0	43.8
Aerospace and Defense Electronics | All other
Disaggregation of Revenue [Line Items]
Net sales	0.2	0.4	0.4	0.6
Aerospace and Defense Electronics | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	143.1	172.6	299.2	336.0
Aerospace and Defense Electronics | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	0.0	3.4	0.2	6.6
Aerospace and Defense Electronics | US Government
Disaggregation of Revenue [Line Items]
Net sales	57.8	58.5	111.6	108.0
Aerospace and Defense Electronics | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	85.3	117.5	187.8	234.6
Engineered Systems
Disaggregation of Revenue [Line Items]
Net sales	99.5	93.5	196.0	183.2
Engineered Systems | United States
Disaggregation of Revenue [Line Items]
Net sales	99.5	93.5	196.0	183.2
Engineered Systems | Europe
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Engineered Systems | All other
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Engineered Systems | Fixed Price
Disaggregation of Revenue [Line Items]
Net sales	52.7	39.7	103.0	74.6
Engineered Systems | Cost Type
Disaggregation of Revenue [Line Items]
Net sales	46.8	53.8	93.0	108.6
Engineered Systems | US Government
Disaggregation of Revenue [Line Items]
Net sales	96.5	83.8	184.8	163.8
Engineered Systems | Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net sales	$ 3.0	$ 9.7	$ 11.2	$ 19.4