Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill by Segment (Detail) $ in Millions	6 Months Ended
	Jul. 01, 2017 USD ($)
Goodwill [Line Items]
Beginning Balance	$ 895.5
Currency translation	33.5
Acquisitions and related adjustments	(29.8)
Ending Balance	899.2
Commercial & Industrial Group [Member]
Goodwill [Line Items]
Beginning Balance	242.4
Currency translation	19.2
Acquisitions and related adjustments	24.7
Ending Balance	286.3
Snap-on Tools Group [Member]
Goodwill [Line Items]
Beginning Balance	12.5
Ending Balance	12.5
Repair Systems & Information Group [Member]
Goodwill [Line Items]
Beginning Balance	640.6
Currency translation	14.3
Acquisitions and related adjustments	(54.5)
Ending Balance	$ 600.4