Revenue Recognition - Revenue Disaggregation (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 935.8	$ 896.2	$ 2,500.8	$ 2,758.4
Net sales	1,027.4	985.9	2,774.4	3,028.6
Intersegment eliminations
Disaggregation of Revenue [Line Items]
Net sales	(134.1)	(141.4)	(378.2)	(418.7)
Operating Segments
Disaggregation of Revenue [Line Items]
Net sales	1,075.7	1,043.2	2,896.3	3,193.5
Commercial & Industrial Group
Disaggregation of Revenue [Line Items]
Net sales	308.4	335.3	870.2	992.8
Commercial & Industrial Group | Operating Segments
Disaggregation of Revenue [Line Items]
Net sales	308.4	335.3	870.2	992.8
Snap-on Tools Group
Disaggregation of Revenue [Line Items]
Net sales	449.8	385.2	1,149.0	1,201.2
Snap-on Tools Group | Operating Segments
Disaggregation of Revenue [Line Items]
Net sales	449.8	385.2	1,149.0	1,201.2
Repair Systems & Information Group
Disaggregation of Revenue [Line Items]
Net sales	317.5	322.7	877.1	999.5
Repair Systems & Information Group | Operating Segments
Disaggregation of Revenue [Line Items]
Net sales	317.5	322.7	877.1	999.5
Financial Services
Disaggregation of Revenue [Line Items]
Net sales	85.8	84.1	256.3	253.8
Other revenues
Disaggregation of Revenue [Line Items]
Net sales	5.8	5.6	17.3	16.4
Excluding Financial Services
Disaggregation of Revenue [Line Items]
Net sales	941.6	901.8	2,518.1	2,774.8
Excluding Financial Services | Vehicle service professionals
Disaggregation of Revenue [Line Items]
Net sales	728.2	665.6	1,912.6	2,070.1
Excluding Financial Services | All other professionals
Disaggregation of Revenue [Line Items]
Net sales	213.4	236.2	605.5	704.7
Excluding Financial Services | Intersegment eliminations
Disaggregation of Revenue [Line Items]
Net sales	(134.1)	(141.4)	(378.2)	(418.7)
Excluding Financial Services | Operating Segments
Disaggregation of Revenue [Line Items]
Net sales	941.6	901.8	2,518.1	2,774.8
Excluding Financial Services | Commercial & Industrial Group
Disaggregation of Revenue [Line Items]
Net sales	235.7	257.0	667.2	769.5
Excluding Financial Services | Commercial & Industrial Group | Vehicle service professionals
Disaggregation of Revenue [Line Items]
Net sales	22.3	20.8	61.7	64.8
Excluding Financial Services | Commercial & Industrial Group | All other professionals
Disaggregation of Revenue [Line Items]
Net sales	213.4	236.2	605.5	704.7
Excluding Financial Services | Commercial & Industrial Group | Intersegment eliminations
Disaggregation of Revenue [Line Items]
Net sales	72.7	78.3	203.0	223.3
Excluding Financial Services | Commercial & Industrial Group | Operating Segments
Disaggregation of Revenue [Line Items]
Net sales	308.4	335.3	870.2	992.8
Excluding Financial Services | Snap-on Tools Group
Disaggregation of Revenue [Line Items]
Net sales	449.8	385.2	1,149.0	1,201.2
Excluding Financial Services | Snap-on Tools Group | Vehicle service professionals
Disaggregation of Revenue [Line Items]
Net sales	449.8	385.2	1,149.0	1,201.2
Excluding Financial Services | Snap-on Tools Group | All other professionals
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Excluding Financial Services | Snap-on Tools Group | Intersegment eliminations
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Excluding Financial Services | Snap-on Tools Group | Operating Segments
Disaggregation of Revenue [Line Items]
Net sales	449.8	385.2	1,149.0	1,201.2
Excluding Financial Services | Repair Systems & Information Group
Disaggregation of Revenue [Line Items]
Net sales	256.1	259.6	701.9	804.1
Excluding Financial Services | Repair Systems & Information Group | Vehicle service professionals
Disaggregation of Revenue [Line Items]
Net sales	256.1	259.6	701.9	804.1
Excluding Financial Services | Repair Systems & Information Group | All other professionals
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Excluding Financial Services | Repair Systems & Information Group | Intersegment eliminations
Disaggregation of Revenue [Line Items]
Net sales	61.4	63.1	175.2	195.4
Excluding Financial Services | Repair Systems & Information Group | Operating Segments
Disaggregation of Revenue [Line Items]
Net sales	317.5	322.7	877.1	999.5
Excluding Financial Services | Financial Services
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Excluding Financial Services | Financial Services | Vehicle service professionals
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Excluding Financial Services | Financial Services | All other professionals
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Excluding Financial Services | Financial Services | Intersegment eliminations
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Excluding Financial Services | Financial Services | Operating Segments
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Excluding Financial Services | North America
Disaggregation of Revenue [Line Items]
Net sales	679.1	651.2	1,829.1	1,970.8
Excluding Financial Services | North America | Commercial & Industrial Group
Disaggregation of Revenue [Line Items]
Net sales	103.9	125.3	309.7	355.8
Excluding Financial Services | North America | Snap-on Tools Group
Disaggregation of Revenue [Line Items]
Net sales	389.2	337.6	1,007.6	1,039.3
Excluding Financial Services | North America | Repair Systems & Information Group
Disaggregation of Revenue [Line Items]
Net sales	186.0	188.3	511.8	575.7
Excluding Financial Services | North America | Financial Services
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Excluding Financial Services | Europe
Disaggregation of Revenue [Line Items]
Net sales	160.3	148.0	424.4	492.9
Excluding Financial Services | Europe | Commercial & Industrial Group
Disaggregation of Revenue [Line Items]
Net sales	66.8	65.1	188.8	214.8
Excluding Financial Services | Europe | Snap-on Tools Group
Disaggregation of Revenue [Line Items]
Net sales	38.6	28.3	87.2	101.7
Excluding Financial Services | Europe | Repair Systems & Information Group
Disaggregation of Revenue [Line Items]
Net sales	54.9	54.6	148.4	176.4
Excluding Financial Services | Europe | Financial Services
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Excluding Financial Services | All other
Disaggregation of Revenue [Line Items]
Net sales	102.2	102.6	264.6	311.1
Excluding Financial Services | All other | Commercial & Industrial Group
Disaggregation of Revenue [Line Items]
Net sales	65.0	66.6	168.7	198.9
Excluding Financial Services | All other | Snap-on Tools Group
Disaggregation of Revenue [Line Items]
Net sales	22.0	19.3	54.2	60.2
Excluding Financial Services | All other | Repair Systems & Information Group
Disaggregation of Revenue [Line Items]
Net sales	15.2	16.7	41.7	52.0
Excluding Financial Services | All other | Financial Services
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Financial Service
Disaggregation of Revenue [Line Items]
Net sales	85.8	84.1	256.3	253.8
Financial Service | Intersegment eliminations
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Financial Service | Commercial & Industrial Group
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Financial Service | Snap-on Tools Group
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Financial Service | Repair Systems & Information Group
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Financial Service | Financial Services
Disaggregation of Revenue [Line Items]
Net sales	$ 85.8	$ 84.1	$ 256.3	$ 253.8