Segments - Net Sales by Segment (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 28, 2020	Mar. 30, 2019
Segment Reporting Information [Line Items]
Total revenues	$ 938.1	$ 1,007.3
Operating earnings	195.8	249.5
Interest expense	(11.4)	(12.5)
Other income (expense) – net	1.5	1.5
Earnings before income taxes and equity earnings	185.9	238.5
Commercial & Industrial Group
Segment Reporting Information [Line Items]
Total revenues	299.9	322.5
Snap-on Tools Group
Segment Reporting Information [Line Items]
Total revenues	375.9	410.2
Repair Systems & Information Group
Segment Reporting Information [Line Items]
Total revenues	314.6	327.9
Financial Services
Segment Reporting Information [Line Items]
Total revenues	85.9	85.6
Operating Segments
Segment Reporting Information [Line Items]
Total revenues	990.4	1,060.6
Operating earnings	214.3	259.4
Operating Segments \| Commercial & Industrial Group
Segment Reporting Information [Line Items]
Total revenues	299.9	322.5
Operating earnings	31.5	46.5
Operating Segments \| Snap-on Tools Group
Segment Reporting Information [Line Items]
Total revenues	375.9	410.2
Operating earnings	48.6	67.2
Operating Segments \| Repair Systems & Information Group
Segment Reporting Information [Line Items]
Total revenues	314.6	327.9
Operating earnings	77.3	83.6
Operating Segments \| Financial Services
Segment Reporting Information [Line Items]
Operating earnings	56.9	62.1
Intersegment eliminations
Segment Reporting Information [Line Items]
Total revenues	(138.2)	(138.9)
Corporate
Segment Reporting Information [Line Items]
Operating earnings	(18.5)	(9.9)
Excluding Financial Services
Segment Reporting Information [Line Items]
Total revenues	852.2	921.7
Operating earnings	138.9	187.4
Excluding Financial Services \| Commercial & Industrial Group
Segment Reporting Information [Line Items]
Total revenues	227.0	249.5
Excluding Financial Services \| Snap-on Tools Group
Segment Reporting Information [Line Items]
Total revenues	375.9	410.2
Excluding Financial Services \| Repair Systems & Information Group
Segment Reporting Information [Line Items]
Total revenues	249.3	262.0
Excluding Financial Services \| Financial Services
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0
Excluding Financial Services \| Operating Segments
Segment Reporting Information [Line Items]
Total revenues	852.2	921.7
Excluding Financial Services \| Operating Segments \| Commercial & Industrial Group
Segment Reporting Information [Line Items]
Total revenues	299.9	322.5
Excluding Financial Services \| Operating Segments \| Snap-on Tools Group
Segment Reporting Information [Line Items]
Total revenues	375.9	410.2
Excluding Financial Services \| Operating Segments \| Repair Systems & Information Group
Segment Reporting Information [Line Items]
Total revenues	314.6	327.9
Excluding Financial Services \| Operating Segments \| Financial Services
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0
Excluding Financial Services \| Intersegment eliminations
Segment Reporting Information [Line Items]
Total revenues	(138.2)	(138.9)
Excluding Financial Services \| Intersegment eliminations \| Commercial & Industrial Group
Segment Reporting Information [Line Items]
Total revenues	72.9	73.0
Excluding Financial Services \| Intersegment eliminations \| Snap-on Tools Group
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0
Excluding Financial Services \| Intersegment eliminations \| Repair Systems & Information Group
Segment Reporting Information [Line Items]
Total revenues	65.3	65.9
Excluding Financial Services \| Intersegment eliminations \| Financial Services
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0
Financial Service
Segment Reporting Information [Line Items]
Total revenues	85.9	85.6
Operating earnings	56.9	62.1
Financial Service \| Commercial & Industrial Group
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0
Financial Service \| Snap-on Tools Group
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0
Financial Service \| Repair Systems & Information Group
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0
Financial Service \| Financial Services
Segment Reporting Information [Line Items]
Total revenues	85.9	85.6
Financial Service \| Intersegment eliminations
Segment Reporting Information [Line Items]
Total revenues	$ 0.0	$ 0.0

Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

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