Reporting Segment And Geographic Information (Segment Revenue by Geography) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 29, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Dec. 28, 2018	Dec. 29, 2017		Dec. 30, 2016
Revenue from External Customer [Line Items]
Revenue	$ 785.5	$ 795.2	$ 785.5	$ 742.2	$ 699.8	$ 676.2	$ 659.9	$ 610.6	$ 3,108.4	$ 2,646.5	[1]	$ 2,362.1	[1]
Building and Infrastructure [Member]
Revenue from External Customer [Line Items]
Revenue									1,065.5	829.4		741.8
Geospatial [Member]
Revenue from External Customer [Line Items]
Revenue									723.1	658.5		635.7
Resources and Utilities [Member]
Revenue from External Customer [Line Items]
Revenue									567.1	481.0		397.4
Transportation [Member]
Revenue from External Customer [Line Items]
Revenue									752.7	677.6		587.2
Operating Segments [Member]
Revenue from External Customer [Line Items]
Revenue									3,132.0	2,649.3	[2]	2,364.7	[2]
Operating Segments [Member] | Building and Infrastructure [Member]
Revenue from External Customer [Line Items]
Revenue									1,087.7	830.5	[2]	742.8	[2]
Operating Segments [Member] | Geospatial [Member]
Revenue from External Customer [Line Items]
Revenue									723.1	658.5	[2]	635.7	[2]
Operating Segments [Member] | Resources and Utilities [Member]
Revenue from External Customer [Line Items]
Revenue									568.1	482.0	[2]	398.2	[2]
Operating Segments [Member] | Transportation [Member]
Revenue from External Customer [Line Items]
Revenue									753.1	678.3	[2]	588.0	[2]
North America [Member] | Operating Segments [Member]
Revenue from External Customer [Line Items]
Revenue									1,670.0	1,412.6	[2]	1,277.9	[2]
North America [Member] | Operating Segments [Member] | Building and Infrastructure [Member]
Revenue from External Customer [Line Items]
Revenue									595.0	428.5	[2]	395.6	[2]
North America [Member] | Operating Segments [Member] | Geospatial [Member]
Revenue from External Customer [Line Items]
Revenue									290.6	257.5	[2]	255.5	[2]
North America [Member] | Operating Segments [Member] | Resources and Utilities [Member]
Revenue from External Customer [Line Items]
Revenue									175.0	163.7	[2]	150.6	[2]
North America [Member] | Operating Segments [Member] | Transportation [Member]
Revenue from External Customer [Line Items]
Revenue									609.4	562.9	[2]	476.2	[2]
Europe [Member] | Operating Segments [Member]
Revenue from External Customer [Line Items]
Revenue									873.5	687.2	[2]	576.2	[2]
Europe [Member] | Operating Segments [Member] | Building and Infrastructure [Member]
Revenue from External Customer [Line Items]
Revenue									312.1	237.9	[2]	207.0	[2]
Europe [Member] | Operating Segments [Member] | Geospatial [Member]
Revenue from External Customer [Line Items]
Revenue									211.2	187.1	[2]	172.8	[2]
Europe [Member] | Operating Segments [Member] | Resources and Utilities [Member]
Revenue from External Customer [Line Items]
Revenue									260.0	189.5	[2]	133.5	[2]
Europe [Member] | Operating Segments [Member] | Transportation [Member]
Revenue from External Customer [Line Items]
Revenue									90.2	72.7	[2]	62.9	[2]
Asia Pacific [Member] | Operating Segments [Member]
Revenue from External Customer [Line Items]
Revenue									418.3	380.0	[2]	352.8	[2]
Asia Pacific [Member] | Operating Segments [Member] | Building and Infrastructure [Member]
Revenue from External Customer [Line Items]
Revenue									152.7	127.2	[2]	105.0	[2]
Asia Pacific [Member] | Operating Segments [Member] | Geospatial [Member]
Revenue from External Customer [Line Items]
Revenue									171.7	162.5	[2]	159.9	[2]
Asia Pacific [Member] | Operating Segments [Member] | Resources and Utilities [Member]
Revenue from External Customer [Line Items]
Revenue									46.4	52.6	[2]	53.5	[2]
Asia Pacific [Member] | Operating Segments [Member] | Transportation [Member]
Revenue from External Customer [Line Items]
Revenue									47.5	37.7	[2]	34.4	[2]
Rest of World [Member] | Operating Segments [Member]
Revenue from External Customer [Line Items]
Revenue									170.2	169.5	[2]	157.8	[2]
Rest of World [Member] | Operating Segments [Member] | Building and Infrastructure [Member]
Revenue from External Customer [Line Items]
Revenue									27.9	36.9	[2]	35.2	[2]
Rest of World [Member] | Operating Segments [Member] | Geospatial [Member]
Revenue from External Customer [Line Items]
Revenue									49.6	51.4	[2]	47.5	[2]
Rest of World [Member] | Operating Segments [Member] | Resources and Utilities [Member]
Revenue from External Customer [Line Items]
Revenue									86.7	76.2	[2]	60.6	[2]
Rest of World [Member] | Operating Segments [Member] | Transportation [Member]
Revenue from External Customer [Line Items]
Revenue									$ 6.0	$ 5.0	[2]	$ 14.5	[2]

[1] See Note 2 for a summary of adjustments

[2] Adjusted to reflect adoption of the new revenue recognition standard, Revenue from Contracts with Customers. For further information, see Note 2.