Business Combinations (Changes In Carrying Amount Of Goodwill By Operating Segment) (Detail) $ in Millions	9 Months Ended
	Sep. 28, 2018 USD ($)
Goodwill [Line Items]
Balance as of fiscal year 2017	$ 2,287.1	[1]
Additions due to acquisitions	1,280.5
Purchase price adjustments- prior years' acquisitions	(1.1)
Foreign currency translation adjustments	(16.1)
Divestiture (1)	(1.8)	[2]
Balance as of the end of the third quarter of fiscal 2018	3,548.6
Buildings and Infrastructure [Member]
Goodwill [Line Items]
Balance as of fiscal year 2017	706.8
Additions due to acquisitions	1,280.5
Purchase price adjustments- prior years' acquisitions	0.0
Foreign currency translation adjustments	(4.2)
Divestiture (1)	0.0	[2]
Balance as of the end of the third quarter of fiscal 2018	1,983.1
Geospatial [Member]
Goodwill [Line Items]
Balance as of fiscal year 2017	415.3
Purchase price adjustments- prior years' acquisitions	0.0
Foreign currency translation adjustments	(5.4)
Divestiture (1)	(1.8)	[2]
Balance as of the end of the third quarter of fiscal 2018	408.1
Resources and Utilities [Member]
Goodwill [Line Items]
Balance as of fiscal year 2017	314.5
Purchase price adjustments- prior years' acquisitions	(0.4)
Foreign currency translation adjustments	(4.1)
Divestiture (1)	0.0	[2]
Balance as of the end of the third quarter of fiscal 2018	310.0
Transportation [Member]
Goodwill [Line Items]
Balance as of fiscal year 2017	850.5
Purchase price adjustments- prior years' acquisitions	(0.7)
Foreign currency translation adjustments	(2.4)
Divestiture (1)	0.0	[2]
Balance as of the end of the third quarter of fiscal 2018	$ 847.4

[1] See Note 2 for a summary of adjustments

[2] In the first quarter of 2018, the Company sold its Geoline business, which was part of the Geospatial segment.