Acquired Finite And Indefinite Lived Intangible Assets [Line Items]

No definition available.

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

- Definition

Customer relationship contractual term maximum.

+ References

No definition available.

+ Details

Name:	sna_CustomerRelationshipContractualTermMaximum
Namespace Prefix:	sna_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Customer relationship contractual term minimum.

+ References

No definition available.

+ Details

Name:	sna_CustomerRelationshipContractualTermMinimum
Namespace Prefix:	sna_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

+ Details

Name:	us-gaap_AmortizationOfIntangibleAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

+ Details

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e961-128460

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillPurchaseAccountingAdjustments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase in assets, excluding financial assets and goodwill, lacking physical substance with an indefinite life, from an acquisition.

+ References

No definition available.

+ Details

Name:	us-gaap_IndefinitelivedIntangibleAssetsAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=sna_RepairSystemsAndInformationGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=sna_CommercialAndIndustrialGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=sna_NorbarAcquisitionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=sna_BTCAcquisitionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=sna_TorqueControlSpecialistsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=sna_CarOLinerHoldingABMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_TrademarksMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=sna_RyesonCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_CustomerRelationshipsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=sna_BTCAcquisitionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=sna_NorbarAcquisitionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	$ 924.1	$ 895.5	$ 790.1
Gross carrying value, Total	$ 415.9	367.9
Weighted-average amortization period (in years)	11 years
Aggregate amortization expense	$ 27.6	24.2	24.7
Estimated annual amortization expense for fiscal period 2018	25.4
Estimated annual amortization expense for fiscal period 2019	21.8
Estimated annual amortization expense for fiscal period 2020	16.8
Estimated annual amortization expense for fiscal period 2021	14.4
Estimated annual amortization expense for fiscal period 2022	13.4
Repair Systems & Information Group [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	613.2	640.6	524.5
Increase (decrease) in goodwill associated with acquisition	(49.1)
Commercial & Industrial Group [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	298.4	242.4	$ 253.1
Increase (decrease) in goodwill associated with acquisition	(1.7)
Norbar [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	23.7
BTC [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	5.9
Torque Control Specialists Pty Ltd [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	1.9
Car-O-Liner Holding AB [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	77.3
Increase (decrease) in goodwill associated with acquisition	(50.8)
Car-O-Liner Holding AB [Member] \| Trademarks [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Gross carrying value, Total	29.8
Car-O-Liner Holding AB [Member] \| Repair Systems & Information Group [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	76.5
Car-O-Liner Holding AB [Member] \| Commercial & Industrial Group [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	0.8
Ryeson Corporation [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	5.0
Increase (decrease) in goodwill associated with acquisition	(1.8)
Customer relationships [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Gross carrying value, Total	$ 175.2	$ 142.6
Weighted-average amortization period (in years)	15 years
Customer relationship contractual term, minimum (in years)	3 years
Customer relationship contractual term, maximum (in years)	5 years
Customer relationships [Member] \| Norbar [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Gross carrying value, Total	$ 1.1
Customer relationships [Member] \| BTC [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Gross carrying value, Total	1.2
Customer relationships [Member] \| Car-O-Liner Holding AB [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Gross carrying value, Total	28.8
BTC [Member] \| Trademarks [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Gross carrying value, Total	2.1
Norbar [Member] \| Trademarks [Member]
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Gross carrying value, Total	$ 16.9