Quarterly Data - Schedule of Quarterly Data (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Jan. 02, 2016	Oct. 03, 2015	Jul. 04, 2015	Apr. 04, 2015	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Quarterly Financial Data [Abstract]
Net sales	$ 889.8	$ 834.1	$ 872.3	$ 834.2	$ 851.7	$ 821.5	$ 851.8	$ 827.8	$ 3,430.4	$ 3,352.8	$ 3,277.7
Gross profit	443.9	419.1	431.3	415.3	412.3	406.9	419.0	410.1	1,709.6	1,648.3	1,584.3
Financial services revenue	74.2	71.6	69.3	66.3	63.1	61.1	58.7	57.4	281.4	240.3	214.9
Financial services expenses	(22.6)	(21.0)	(19.8)	(19.3)	(18.1)	(17.6)	(17.3)	(17.1)	(82.7)	(70.1)	(65.8)
Net earnings	149.7	135.2	143.4	131.3	134.5	119.9	123.0	113.2	559.6	490.6	432.1
Net earnings attributable to Snap-on Incorporated	$ 146.3	$ 131.7	$ 140.1	$ 128.3	$ 131.4	$ 116.8	$ 120.0	$ 110.5	$ 546.4	$ 478.7	$ 421.9
Earnings per share - basic	$ 2.52	$ 2.27	$ 2.41	$ 2.21	$ 2.26	$ 2.01	$ 2.07	$ 1.90	$ 9.40	$ 8.24	$ 7.26
Earnings per share - diluted	2.47	2.22	2.36	2.16	2.22	1.98	2.03	1.87	9.20	8.10	7.14
Cash dividends paid per share	$ 0.71	$ 0.61	$ 0.61	$ 0.61	$ 0.61	$ 0.53	$ 0.53	$ 0.53	$ 2.54	$ 2.20	$ 1.85