Segments - Assets by Segment (Detail) (USD $) In Millions, unless otherwise specified	Sep. 27, 2014	Dec. 28, 2013
Segment Reporting Information [Line Items]
Assets	$ 4,268.5	$ 4,110.0
Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	3,985.4	3,731.9
Operating Segments [Member] | Commercial & Industrial Group [Member]
Segment Reporting Information [Line Items]
Assets	989.9	971.0
Operating Segments [Member] | Snap-on Tools Group [Member]
Segment Reporting Information [Line Items]
Assets	616.9	557.3
Operating Segments [Member] | Repair Systems & Information Group [Member]
Segment Reporting Information [Line Items]
Assets	1,030.1	979.6
Operating Segments [Member] | Financial Services [Member]
Segment Reporting Information [Line Items]
Assets	1,348.5	1,224.0
Corporate [Member]
Segment Reporting Information [Line Items]
Assets	330.2	431.8
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Assets	$ (47.1)	$ (53.7)