Segments - Net Sales by Segment (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Oct. 02, 2021	Sep. 26, 2020	Oct. 02, 2021	Sep. 26, 2020
Segment Reporting Information [Line Items]
Total revenues	$ 1,125.0	$ 1,027.4	$ 3,406.5	$ 2,774.4
Operating earnings	271.9	251.3	824.1	595.8
Interest expense	(13.2)	(13.8)	(41.8)	(38.6)
Other income (expense) – net	3.7	2.8	11.4	6.3
Earnings before income taxes and equity earnings	262.4	240.3	793.7	563.5
Commercial & Industrial Group
Segment Reporting Information [Line Items]
Total revenues	351.4	308.4	1,047.6	870.2
Snap-on Tools Group
Segment Reporting Information [Line Items]
Total revenues	471.4	449.8	1,433.8	1,149.0
Repair Systems & Information Group
Segment Reporting Information [Line Items]
Total revenues	364.4	317.5	1,110.6	877.1
Financial Services
Segment Reporting Information [Line Items]
Total revenues	87.3	85.8	262.8	256.3
Operating Segments
Segment Reporting Information [Line Items]
Total revenues	1,187.2	1,075.7	3,592.0	2,896.3
Operating earnings	305.7	275.9	916.6	659.7
Operating Segments \| Commercial & Industrial Group
Segment Reporting Information [Line Items]
Total revenues	351.4	308.4	1,047.6	870.2
Operating earnings	53.6	43.1	159.8	97.5
Operating Segments \| Snap-on Tools Group
Segment Reporting Information [Line Items]
Total revenues	471.4	449.8	1,433.8	1,149.0
Operating earnings	98.2	87.1	300.6	174.1
Operating Segments \| Repair Systems & Information Group
Segment Reporting Information [Line Items]
Total revenues	364.4	317.5	1,110.6	877.1
Operating earnings	83.3	80.1	251.4	208.0
Operating Segments \| Financial Services
Segment Reporting Information [Line Items]
Operating earnings	70.6	65.6	204.8	180.1
Intersegment eliminations
Segment Reporting Information [Line Items]
Total revenues	(149.5)	(134.1)	(448.3)	(378.2)
Corporate
Segment Reporting Information [Line Items]
Operating earnings	(33.8)	(24.6)	(92.5)	(63.9)
Excluding Financial Services
Segment Reporting Information [Line Items]
Total revenues	1,037.7	941.6	3,143.7	2,518.1
Operating earnings	201.3	185.7	619.3	415.7
Excluding Financial Services \| Commercial & Industrial Group
Segment Reporting Information [Line Items]
Total revenues	271.7	235.7	817.5	667.2
Excluding Financial Services \| Snap-on Tools Group
Segment Reporting Information [Line Items]
Total revenues	471.4	449.8	1,433.8	1,149.0
Excluding Financial Services \| Repair Systems & Information Group
Segment Reporting Information [Line Items]
Total revenues	294.6	256.1	892.4	701.9
Excluding Financial Services \| Financial Services
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0	0.0	0.0
Excluding Financial Services \| Operating Segments
Segment Reporting Information [Line Items]
Total revenues	1,037.7	941.6	3,143.7	2,518.1
Excluding Financial Services \| Operating Segments \| Commercial & Industrial Group
Segment Reporting Information [Line Items]
Total revenues	351.4	308.4	1,047.6	870.2
Excluding Financial Services \| Operating Segments \| Snap-on Tools Group
Segment Reporting Information [Line Items]
Total revenues	471.4	449.8	1,433.8	1,149.0
Excluding Financial Services \| Operating Segments \| Repair Systems & Information Group
Segment Reporting Information [Line Items]
Total revenues	364.4	317.5	1,110.6	877.1
Excluding Financial Services \| Operating Segments \| Financial Services
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0	0.0	0.0
Excluding Financial Services \| Intersegment eliminations
Segment Reporting Information [Line Items]
Total revenues	(149.5)	(134.1)	(448.3)	(378.2)
Excluding Financial Services \| Intersegment eliminations \| Commercial & Industrial Group
Segment Reporting Information [Line Items]
Total revenues	79.7	72.7	230.1	203.0
Excluding Financial Services \| Intersegment eliminations \| Snap-on Tools Group
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0	0.0	0.0
Excluding Financial Services \| Intersegment eliminations \| Repair Systems & Information Group
Segment Reporting Information [Line Items]
Total revenues	69.8	61.4	218.2	175.2
Excluding Financial Services \| Intersegment eliminations \| Financial Services
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0	0.0	0.0
Financial Service
Segment Reporting Information [Line Items]
Total revenues	87.3	85.8	262.8	256.3
Operating earnings	70.6	65.6	204.8	180.1
Financial Service \| Commercial & Industrial Group
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0	0.0	0.0
Financial Service \| Snap-on Tools Group
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0	0.0	0.0
Financial Service \| Repair Systems & Information Group
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0	0.0	0.0
Financial Service \| Financial Services
Segment Reporting Information [Line Items]
Total revenues	87.3	85.8	262.8	256.3
Financial Service \| Intersegment eliminations
Segment Reporting Information [Line Items]
Total revenues	$ 0.0	$ 0.0	$ 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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