Segments - Net Sales by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 28, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 29, 2012	Sep. 29, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Net sales	$ 797.5	$ 753.2	$ 764.1	$ 741.7	$ 753.2	$ 711.6	$ 737.9	$ 735.2	$ 3,056.5	$ 2,937.9	$ 2,854.2
Financial services revenue	47.4	45.1	44.5	44.0	42.9	40.5	39.9	38.0	181.0	161.3	124.3
Total revenues									3,237.5	3,099.2	2,978.5
Operating earnings									586.2	516.4	475.1
Interest expense									(56.1)	(55.8)	(61.2)
Other income (expense) - net									(3.9)	(0.4)	(1.0)
Earnings before income taxes and equity earnings									526.2	460.2	412.9
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales									3,459.0	3,315.0	3,199.8
Operating earnings									689.5	616.1	557.5
Operating Segments [Member] | Commercial & Industrial Group [Member]
Segment Reporting Information [Line Items]
Net sales									1,091.0	1,125.9	1,125.8
Operating earnings									137.3	127.3	123.4
Operating Segments [Member] | Snap-on Tools Group [Member]
Segment Reporting Information [Line Items]
Net sales									1,358.4	1,272.0	1,153.4
Operating earnings									194.6	176.4	158.5
Operating Segments [Member] | Repair Systems & Information Group [Member]
Segment Reporting Information [Line Items]
Net sales									1,009.6	917.1	920.6
Operating earnings									231.9	205.7	184.7
Operating Segments [Member] | Financial Services [Member]
Segment Reporting Information [Line Items]
Operating earnings									125.7	106.7	90.9
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales									(402.5)	(377.1)	(345.6)
Corporate [Member]
Segment Reporting Information [Line Items]
Operating earnings									$ (103.3)	$ (99.7)	$ (82.4)