Segment Information - Identifiable Assets (Details) - USD ($) $ in Millions	Apr. 04, 2021	Jan. 03, 2021
Segment Reporting Information [Line Items]
Identifiable assets	$ 7,618.4	$ 5,084.8
Operating segments | Instrumentation
Segment Reporting Information [Line Items]
Identifiable assets	1,663.3	1,676.2
Operating segments | Digital Imaging
Segment Reporting Information [Line Items]
Identifiable assets	1,984.4	2,000.8
Operating segments | Aerospace and Defense Electronics
Segment Reporting Information [Line Items]
Identifiable assets	540.9	567.6
Operating segments | Engineered Systems
Segment Reporting Information [Line Items]
Identifiable assets	163.1	175.1
Corporate expense
Segment Reporting Information [Line Items]
Identifiable assets	$ 3,266.7	$ 665.1