Segments - Assets by Segment (Detail) - USD ($) $ in Millions	Jul. 04, 2015	Jan. 03, 2015
Segment Reporting Information [Line Items]
Assets	$ 4,390.7	$ 4,310.1
Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	4,059.1	3,944.9
Operating Segments [Member] | Commercial & Industrial Group [Member]
Segment Reporting Information [Line Items]
Assets	931.6	939.7
Operating Segments [Member] | Snap-on Tools Group [Member]
Segment Reporting Information [Line Items]
Assets	637.3	600.1
Operating Segments [Member] | Repair Systems & Information Group [Member]
Segment Reporting Information [Line Items]
Assets	1,037.6	1,036.8
Operating Segments [Member] | Financial Services [Member]
Segment Reporting Information [Line Items]
Assets	1,452.6	1,368.3
Corporate [Member]
Segment Reporting Information [Line Items]
Assets	378.8	401.7
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Assets	$ (47.2)	$ (36.5)