Business Segments Business Segments (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 29, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 30, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Net Sales	$ 834.2	$ 802.2	$ 782.0	$ 745.2	$ 748.4	$ 725.3	$ 732.5	$ 695.6	$ 3,163.6	$ 2,901.8	$ 2,603.8
Instrumentation
Disaggregation of Revenue [Line Items]
Net Sales									1,105.1	1,021.2	953.9
Digital Imaging
Disaggregation of Revenue [Line Items]
Net Sales									992.9	875.3
Aerospace and Defense Electronics
Disaggregation of Revenue [Line Items]
Net Sales									690.1	640.2
Engineered Systems
Disaggregation of Revenue [Line Items]
Net Sales									375.5	365.1
United States
Disaggregation of Revenue [Line Items]
Net Sales									2,179.6	2,044.9	$ 1,849.4
United States | Instrumentation
Disaggregation of Revenue [Line Items]
Net Sales									899.7	835.0
United States | Digital Imaging
Disaggregation of Revenue [Line Items]
Net Sales									316.1	239.3
United States | Aerospace and Defense Electronics
Disaggregation of Revenue [Line Items]
Net Sales									588.3	605.5
United States | Engineered Systems
Disaggregation of Revenue [Line Items]
Net Sales									375.5	365.1
Europe
Disaggregation of Revenue [Line Items]
Net Sales									565.0	437.3
Europe | Instrumentation
Disaggregation of Revenue [Line Items]
Net Sales									164.8	134.6
Europe | Digital Imaging
Disaggregation of Revenue [Line Items]
Net Sales									299.4	270.2
Europe | Aerospace and Defense Electronics
Disaggregation of Revenue [Line Items]
Net Sales									100.8	32.5
Europe | Engineered Systems
Disaggregation of Revenue [Line Items]
Net Sales									0.0	0.0
All other
Disaggregation of Revenue [Line Items]
Net Sales									419.0	419.6
All other | Instrumentation
Disaggregation of Revenue [Line Items]
Net Sales									40.6	51.6
All other | Digital Imaging
Disaggregation of Revenue [Line Items]
Net Sales									377.4	365.8
All other | Aerospace and Defense Electronics
Disaggregation of Revenue [Line Items]
Net Sales									1.0	2.2
All other | Engineered Systems
Disaggregation of Revenue [Line Items]
Net Sales									0.0	0.0
Fixed Price
Disaggregation of Revenue [Line Items]
Net Sales									2,854.2	2,599.7
Fixed Price | Instrumentation
Disaggregation of Revenue [Line Items]
Net Sales									1,094.4	1,001.0
Fixed Price | Digital Imaging
Disaggregation of Revenue [Line Items]
Net Sales									903.1	795.5
Fixed Price | Aerospace and Defense Electronics
Disaggregation of Revenue [Line Items]
Net Sales									687.8	637.4
Fixed Price | Engineered Systems
Disaggregation of Revenue [Line Items]
Net Sales									168.9	165.8
Cost Type
Disaggregation of Revenue [Line Items]
Net Sales									309.4	302.1
Cost Type | Instrumentation
Disaggregation of Revenue [Line Items]
Net Sales									10.7	20.2
Cost Type | Digital Imaging
Disaggregation of Revenue [Line Items]
Net Sales									89.8	79.8
Cost Type | Aerospace and Defense Electronics
Disaggregation of Revenue [Line Items]
Net Sales									2.3	2.8
Cost Type | Engineered Systems
Disaggregation of Revenue [Line Items]
Net Sales									206.6	199.3
United States Government
Disaggregation of Revenue [Line Items]
Net Sales									752.0	655.3
United States Government | Instrumentation
Disaggregation of Revenue [Line Items]
Net Sales									80.4	68.3
United States Government | Digital Imaging
Disaggregation of Revenue [Line Items]
Net Sales									107.4	90.5
United States Government | Aerospace and Defense Electronics
Disaggregation of Revenue [Line Items]
Net Sales									225.3	177.2
United States Government | Engineered Systems
Disaggregation of Revenue [Line Items]
Net Sales									338.9	319.3
Other, Primarily Commercial
Disaggregation of Revenue [Line Items]
Net Sales									2,411.6	2,246.5
Other, Primarily Commercial | Instrumentation
Disaggregation of Revenue [Line Items]
Net Sales									1,024.7	952.9
Other, Primarily Commercial | Digital Imaging
Disaggregation of Revenue [Line Items]
Net Sales									885.5	784.8
Other, Primarily Commercial | Aerospace and Defense Electronics
Disaggregation of Revenue [Line Items]
Net Sales									464.8	463.0
Other, Primarily Commercial | Engineered Systems
Disaggregation of Revenue [Line Items]
Net Sales									$ 36.6	$ 45.8