Segments - Assets by Segment (Detail) - USD ($) $ in Millions	Jul. 02, 2016	Jan. 02, 2016
Segment Reporting Information [Line Items]
Assets	$ 4,505.1	$ 4,331.1
Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	4,326.6	4,162.3
Operating Segments [Member] | Commercial & Industrial Group [Member]
Segment Reporting Information [Line Items]
Assets	920.1	901.6
Operating Segments [Member] | Snap-on Tools Group [Member]
Segment Reporting Information [Line Items]
Assets	658.8	646.7
Operating Segments [Member] | Repair Systems & Information Group [Member]
Segment Reporting Information [Line Items]
Assets	1,057.2	1,041.6
Operating Segments [Member] | Financial Services [Member]
Segment Reporting Information [Line Items]
Assets	1,690.5	1,572.4
Corporate [Member]
Segment Reporting Information [Line Items]
Assets	240.8	203.6
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Assets	$ (62.3)	$ (34.8)