Geographic Valuation Methodologies of Inventory [Line Items]

No definition available.

Name:	sna_GeographicValuationMethodologiesOfInventoryLineItems
Namespace Prefix:	sna_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The effect of liquidating LIFO (last in first out) inventory layers on income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SAB Topic 11.F)
-URI http://asc.fasb.org/extlink&oid=27011343&loc=d3e100079-122729

+ Details

Name:	us-gaap_EffectOfLIFOInventoryLiquidationOnIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The percentage of FIFO (first in first out) inventory to total inventory as of the balance sheet date if other than 100 percent.

+ References

No definition available.

+ Details

Name:	us-gaap_PercentageOfFIFOInventory
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The percentage of LIFO (last in first out) inventory to total inventory as of the balance sheet date if other than 100 percent.

+ References

No definition available.

+ Details

Name:	us-gaap_PercentageOfLIFOInventory
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	srt_StatementGeographicalAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Inventories - Narrative (Detail) - USD ($)	3 Months Ended		6 Months Ended
Inventories - Narrative (Detail) - USD ($)	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018	Dec. 29, 2018
Geographic Valuation Methodologies Of Inventory [Line Items]
Percentage of FIFO Inventory	60.00%		60.00%		61.00%
Effect of LIFO inventory liquidation on income	$ 0	$ 0	$ 0	$ 0
United States
Geographic Valuation Methodologies Of Inventory [Line Items]
Percentage of FIFO Inventory	34.00%		34.00%
Percentage of LIFO Inventory	66.00%		66.00%