Exit and Disposal Activities - Summary of Exit and Disposal Activities (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 26, 2020	Sep. 26, 2020
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs	$ 0.0	$ 11.5
Commercial & Industrial Group
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs		6.4
Repair Systems & Information Group
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs		4.5
Snap-on Tools Group
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs		0.6
Cost of goods sold:
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs		7.1
Cost of goods sold: | Commercial & Industrial Group
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs		6.4
Cost of goods sold: | Repair Systems & Information Group
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs		0.7
Operating Expenses:
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs		4.4
Operating Expenses: | Repair Systems & Information Group
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs		3.8
Operating Expenses: | Snap-on Tools Group
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs		$ 0.6