Reporting Segment And Geographic Information (Schedule Of Revenue, Operating Income And Identifiable Assets By Segment) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Jan. 01, 2021	Jan. 03, 2020
Segment Reporting Information [Line Items]
Revenue	$ 3,659.1	$ 3,147.7	$ 3,264.3
Revenue purchase accounting adjustments	0.3	4.3	7.0
Operating income purchase accounting adjustments	(4.1)	(1.2)	0.7
Segment revenue	3,659.4	3,152.0	3,271.3
Operating income	561.0	419.8	375.9
Depreciation expense	41.3	39.7	39.4
Buildings and Infrastructure
Segment Reporting Information [Line Items]
Revenue	1,422.5	1,230.7	1,254.2
Revenue purchase accounting adjustments	0.2	0.3	4.0
Operating income purchase accounting adjustments	(3.9)	(4.9)	(2.2)
Segment revenue	1,422.7	1,231.0	1,258.2
Geospatial
Segment Reporting Information [Line Items]
Revenue	828.9	650.5	649.4
Revenue purchase accounting adjustments	0.0	0.0	0.0
Operating income purchase accounting adjustments	0.0	0.0	0.0
Segment revenue	828.9	650.5	649.4
Resources and Utilities
Segment Reporting Information [Line Items]
Revenue	771.3	627.3	568.4
Revenue purchase accounting adjustments	0.0	2.7	3.0
Operating income purchase accounting adjustments	0.0	2.6	2.9
Segment revenue	771.3	630.0	571.4
Transportation
Segment Reporting Information [Line Items]
Revenue	636.4	639.2	792.3
Revenue purchase accounting adjustments	0.1	1.3	0.0
Operating income purchase accounting adjustments	(0.2)	1.1	0.0
Segment revenue	636.5	640.5	792.3
Operating Income
Segment Reporting Information [Line Items]
Operating income	967.3	794.8	746.4
Operating Income | Buildings and Infrastructure
Segment Reporting Information [Line Items]
Operating income	415.6	343.0	322.1
Operating Income | Geospatial
Segment Reporting Information [Line Items]
Operating income	244.1	184.4	132.2
Operating Income | Resources and Utilities
Segment Reporting Information [Line Items]
Operating income	264.0	218.4	166.2
Operating Income | Transportation
Segment Reporting Information [Line Items]
Operating income	43.6	49.0	125.9
Segments Revenue
Segment Reporting Information [Line Items]
Operating income	963.2	793.6	747.1
Depreciation expense	24.0	24.0	23.2
Segments Revenue | Buildings and Infrastructure
Segment Reporting Information [Line Items]
Operating income	411.7	338.1	319.9
Depreciation expense	7.0	8.1	8.1
Segments Revenue | Geospatial
Segment Reporting Information [Line Items]
Operating income	244.1	184.4	132.2
Depreciation expense	7.0	6.2	6.3
Segments Revenue | Resources and Utilities
Segment Reporting Information [Line Items]
Operating income	264.0	221.0	169.1
Depreciation expense	5.9	5.6	4.4
Segments Revenue | Transportation
Segment Reporting Information [Line Items]
Operating income	43.4	50.1	125.9
Depreciation expense	$ 4.1	$ 4.1	$ 4.4