Segment Information (Schedule Of Revenue, Operating Income And Identifiable Assets By Segment) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Segment Reporting Information [Line Items]
Revenue	$ 945.2	$ 733.6	$ 1,831.7	$ 1,525.9
Acquired deferred revenue adjustment	0.1	1.6	0.3	3.3
Segment revenue	945.3	735.2	1,832.0	1,529.2
Amortization of acquired capitalized commissions	(1.1)	(1.4)	(2.3)	(2.9)
Consolidated segment operating income	144.8	97.6	285.7	195.9
Depreciation expense			20.8	19.5
Segment Reconciling
Segment Reporting Information [Line Items]
Consolidated segment operating income	254.5	186.1	489.1	361.0
Operating segment
Segment Reporting Information [Line Items]
Consolidated segment operating income	253.5	186.3	487.1	361.4
Depreciation expense	6.2	5.9	12.1	11.8
Buildings and Infrastructure
Segment Reporting Information [Line Items]
Revenue	364.7	295.2	707.7	592.0
Acquired deferred revenue adjustment	0.1	0.1	0.2	0.2
Segment revenue	364.8	295.3	707.9	592.2
Amortization of acquired capitalized commissions	(1.1)	(1.3)	(2.2)	(2.7)
Buildings and Infrastructure | Segment Reconciling
Segment Reporting Information [Line Items]
Consolidated segment operating income	105.1	86.6	202.5	148.7
Buildings and Infrastructure | Operating segment
Segment Reporting Information [Line Items]
Consolidated segment operating income	104.1	85.4	200.5	146.2
Depreciation expense	1.8	2.0	3.6	4.1
Geospatial
Segment Reporting Information [Line Items]
Revenue	219.7	145.2	401.4	291.4
Acquired deferred revenue adjustment	0.0	0.0	0.0	0.0
Segment revenue	219.7	145.2	401.4	291.4
Amortization of acquired capitalized commissions	0.0	0.0	0.0	0.0
Geospatial | Segment Reconciling
Segment Reporting Information [Line Items]
Consolidated segment operating income	66.1	37.4	114.8	67.9
Geospatial | Operating segment
Segment Reporting Information [Line Items]
Consolidated segment operating income	66.1	37.4	114.8	67.9
Depreciation expense	1.8	1.5	3.5	2.9
Resources and Utilities
Segment Reporting Information [Line Items]
Revenue	197.5	142.9	402.7	321.9
Acquired deferred revenue adjustment	0.0	0.9	0.0	2.2
Segment revenue	197.5	143.8	402.7	324.1
Amortization of acquired capitalized commissions	0.0	(0.1)	0.0	(0.1)
Resources and Utilities | Segment Reconciling
Segment Reporting Information [Line Items]
Consolidated segment operating income	70.5	48.3	150.6	113.9
Resources and Utilities | Operating segment
Segment Reporting Information [Line Items]
Consolidated segment operating income	70.5	49.1	150.6	116.0
Depreciation expense	1.5	1.3	3.0	2.6
Transportation
Segment Reporting Information [Line Items]
Revenue	163.3	150.3	319.9	320.6
Acquired deferred revenue adjustment	0.0	0.6	0.1	0.9
Segment revenue	163.3	150.9	320.0	321.5
Amortization of acquired capitalized commissions	0.0	0.0	(0.1)	(0.1)
Transportation | Segment Reconciling
Segment Reporting Information [Line Items]
Consolidated segment operating income	12.8	13.8	21.2	30.5
Transportation | Operating segment
Segment Reporting Information [Line Items]
Consolidated segment operating income	12.8	14.4	21.2	31.3
Depreciation expense	$ 1.1	$ 1.1	$ 2.0	$ 2.2