Segments - Net Sales by Segment (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Oct. 03, 2015	Sep. 27, 2014	Oct. 03, 2015	Sep. 27, 2014
Segment Reporting Information [Line Items]
Net sales	$ 821.5	$ 806.3	$ 2,501.1	$ 2,420.3
Financial services revenue	61.1	53.6	177.2	155.5
Total revenues	882.6	859.9	2,678.3	2,575.8
Operating earnings	187.1	168.3	557.5	497.3
Interest expense	(13.0)	(12.7)	(38.9)	(39.1)
Other income (expense) - net	(0.5)	(0.9)	(1.9)	(0.7)
Earnings before income taxes and equity earnings	173.6	154.7	516.7	457.5
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	952.0	925.0	2,871.9	2,756.7
Operating earnings	210.8	191.3	638.1	570.2
Operating Segments [Member] \| Commercial & Industrial Group [Member]
Segment Reporting Information [Line Items]
Net sales	288.5	298.8	881.8	876.6
Operating earnings	41.3	40.8	127.5	118.1
Operating Segments [Member] \| Snap-on Tools Group [Member]
Segment Reporting Information [Line Items]
Net sales	380.6	355.0	1,157.5	1,067.7
Operating earnings	56.3	49.5	184.1	159.2
Operating Segments [Member] \| Repair Systems & Information Group [Member]
Segment Reporting Information [Line Items]
Net sales	282.9	271.2	832.6	812.4
Operating earnings	69.7	63.3	201.3	186.0
Operating Segments [Member] \| Financial Services [Member]
Segment Reporting Information [Line Items]
Operating earnings	43.5	37.7	125.2	106.9
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	(130.5)	(118.7)	(370.8)	(336.4)
Corporate [Member]
Segment Reporting Information [Line Items]
Operating earnings	$ (23.7)	$ (23.0)	$ (80.6)	$ (72.9)

The aggregate financial services revenue and operating interest income earned during the reporting period.

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