Exit And Disposal Activities (Recorded Costs Associated With Exit And Disposal Activities) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012	Oct. 01, 2011
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs	$ 2.3	$ 2.9	$ 16.5	$ 7.8
Commercial & Industrial Group [Member]
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs	2.2	2.4	8.9	3.1
Snap-On Tools Group [Member]
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs	0.1	0.4	7.2	4.0
Repair Systems & Information Group [Member]
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs		0.1	0.4	0.5
Corporate [Member]
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs				0.2
Cost Of Goods Sold [Member]
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs	1.0	0.6	10.9	3.7
Cost Of Goods Sold [Member] | Commercial & Industrial Group [Member]
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs	0.9	0.2	3.6	0.4
Cost Of Goods Sold [Member] | Snap-On Tools Group [Member]
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs	0.1	0.4	7.1	3.4
Cost Of Goods Sold [Member] | Repair Systems & Information Group [Member]
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs			0.2	(0.1)
Operating Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs	1.3	2.3	5.6	4.1
Operating Expenses [Member] | Commercial & Industrial Group [Member]
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs	1.3	2.2	5.3	2.7
Operating Expenses [Member] | Snap-On Tools Group [Member]
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs			0.1	0.6
Operating Expenses [Member] | Repair Systems & Information Group [Member]
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs		0.1	0.2	0.6
Operating Expenses [Member] | Corporate [Member]
Restructuring Cost and Reserve [Line Items]
Exit and disposal costs				$ 0.2