Business Acquisitions, Goodwill and Acquired Intangible Assets (Narrative) (Details) £ / shares in Units, $ / shares in Units, £ in Millions, $ in Millions												3 Months Ended				4 Months Ended	6 Months Ended	12 Months Ended
	Dec. 12, 2016 GBP (£) £ / shares	Dec. 06, 2016 USD ($)	Nov. 02, 2016 USD ($)	May 03, 2016 USD ($)	Apr. 15, 2016 USD ($)	Apr. 06, 2016 USD ($)	Jun. 05, 2015 USD ($)	Apr. 29, 2015 USD ($)	Feb. 02, 2015 USD ($)	Nov. 18, 2014 USD ($) $ / shares	Jun. 30, 2014 USD ($)	Jan. 03, 2016 USD ($)	Sep. 27, 2015 USD ($)	Jun. 28, 2015 USD ($)	Mar. 29, 2015 USD ($)	Apr. 29, 2015 USD ($)	Jul. 01, 2017 GBP (£)	Jan. 01, 2017 USD ($)	Mar. 31, 2016 GBP (£)	Jan. 03, 2016 USD ($)	Dec. 28, 2014 USD ($) business	Dec. 12, 2016 USD ($)	Dec. 29, 2013 USD ($)
Business Acquisition [Line Items]
Noncontrolling interest												$ 0.0	$ 0.0	$ (0.3)	$ 0.0			$ 0.0		$ (0.3)	$ (2.1)
Number of businesses acquired during period | business																					4
Goodwill, net												1,140.2						1,193.5		1,140.2	$ 1,150.6
Acquired intangibles, net												243.3						234.6		243.3
Amortization expense																		28.3		30.6	32.0
Future amortization expense, 2017																		27.3
Future amortization expense, 2018																		24.2
Future amortization expense, 2019																		17.1
Future amortization expense, 2020																		15.2
Future amortization expense, 2021																		$ 14.3
Minimum
Business Acquisition [Line Items]
Amortizable other intangible assets, useful lives																		1 year
Maximum
Business Acquisition [Line Items]
Amortizable other intangible assets, useful lives																		15 years
Acquisitions in 2016
Business Acquisition [Line Items]
Amount spent on acquisitions and other investments																		$ 93.4
Cash paid																		93.4
Goodwill, net																		$ 64.0
Acquisitions in 2015
Business Acquisition [Line Items]
Amount spent on acquisitions and other investments												66.7								66.7
Cash paid																				66.7
Goodwill, net												$ 27.6								$ 27.6
Acquisitions in 2014
Business Acquisition [Line Items]
Amount spent on acquisitions and other investments																					$ 195.8
Number of businesses acquired during period, excluding largest acquisition | business																					3
Ocean Aero [Member]
Business Acquisition [Line Items]
Cash paid																					$ 24.8
Hanson Research
Business Acquisition [Line Items]
Cash paid		$ 25.0
Goodwill, net		$ 13.5
IN USA
Business Acquisition [Line Items]
Cash paid			$ 10.2
Goodwill, net			$ 6.3
CARIS
Business Acquisition [Line Items]
Cash paid				$ 26.2
Goodwill, net				22.2
Quantum Data
Business Acquisition [Line Items]
Cash paid					$ 17.3
Goodwill, net					10.7
Frontline
Business Acquisition [Line Items]
Cash paid						$ 13.7
Goodwill, net						11.3
ICM
Business Acquisition [Line Items]
Cash paid							$ 21.8
Goodwill, net							19.2
Optech
Business Acquisition [Line Items]
Cash paid								$ 22.0
Goodwill, net								$ 0.0								$ 0.0
Bowtech
Business Acquisition [Line Items]
Cash paid									$ 18.9
Goodwill, net									7.0
Subsidiaries | CARIS
Business Acquisition [Line Items]
Cash paid				$ 26.2
Subsidiaries | Quantum Data
Business Acquisition [Line Items]
Cash paid					$ 17.3
Subsidiaries | Frontline
Business Acquisition [Line Items]
Cash paid						$ 13.7
Subsidiaries | ICM
Business Acquisition [Line Items]
Cash paid							21.8
Indemnification holdback							$ 2.5
Subsidiaries | Optech
Business Acquisition [Line Items]
Remaining percentage of voting interests acquired								49.00%								49.00%
Cash paid								$ 22.0
Noncontrolling interest																					41.2		$ 47.0
Noncontrolling interest																$ (0.3)					(2.1)
Translation adjustments																$ 1.3					$ 3.7
Subsidiaries | Bowtech
Business Acquisition [Line Items]
Cash paid									$ 18.9
Subsidiaries | Bolt
Business Acquisition [Line Items]
Cash paid										$ 171.0
Payments to acquire businesses (in usd per share) | $ / shares										$ 22.00
Sales reported by acquired entity for last annual period											$ 67.5
Subsidiaries | e2v
Business Acquisition [Line Items]
Payments to acquire businesses (in usd per share) | £ / shares	£ 0.0275
Aggregate enterprise value	£ 627.1																					$ 788.9
Sales reported by acquired entity for last annual period | £																			£ 236.4
Subsequent Event | Subsidiaries | e2v
Business Acquisition [Line Items]
Value of share capital issued and to be issued purchased | £																	£ 619.6