Summary of Accounting Policies (Policies)	3 Months Ended
Summary of Accounting Policies (Policies)	Mar. 30, 2019
Accounting Policies [Abstract]
Principles of consolidation and presentation	Principles of consolidation and presentation The Condensed Consolidated Financial Statements include the accounts of Snap-on Incorporated and its wholly-owned and majority-owned subsidiaries (collectively, “Snap-on” or the “company”). These financial statements should be read in conjunction with, and have been prepared in conformity with, the accounting principles reflected in the consolidated financial statements and related notes included in Snap-on’s 2018 Annual Report on Form 10-K for the fiscal year ended December 29, 2018 (“2018 year end”). The company’s 2019 fiscal first quarter ended on March 30, 2019; the 2018 fiscal first quarter ended on March 31, 2018. The company’s 2019 and 2018 fiscal first quarters each contained 13 weeks of operating results. Snap-on’s Condensed Consolidated Financial Statements are prepared in conformity with generally accepted accounting principles in the United States of America (“GAAP”). In the opinion of management, all adjustments (consisting of normal recurring adjustments) necessary for the fair presentation of the Condensed Consolidated Financial Statements for the three month periods ended March 30, 2019, and March 31, 2018, have been made. Interim results of operations are not necessarily indicative of the results to be expected for the full fiscal year.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Financial Instruments	Financial Instruments The fair value of the company’s derivative financial instruments is generally determined using quoted prices in active markets for similar assets and liabilities. The carrying value of the company’s non-derivative financial instruments either approximates fair value, due to their short-term nature, or the amount disclosed for fair value is based upon a discounted cash flow analysis or quoted market values. See Note 9 for further information on financial instruments.
Change in Functional Currency	Change in Functional Currency Argentina’s economy has been determined to be highly inflationary effective July 1, 2018. As a result the functional currency for the company’s subsidiary in Argentina changed from the Argentinian Peso to the U.S. Dollar. The impact of the change in functional currency was not material to the Condensed Consolidated Financial Statements for the three months ended March 30, 2019.
New Accounting Standards	New Accounting Standards The following new accounting pronouncements were adopted in fiscal year 2019: On December 30, 2018, the beginning of Snap-on’s 2019 fiscal year, Snap-on adopted ASU No. 2017-12, Derivatives and Hedging (Topic 815) – Targeted Improvements to Accounting for Hedging Activities, which improves the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements. The amendments in this update also make certain targeted improvements to simplify the application of the hedge accounting guidance in current GAAP. The adoption of this ASU did not have a significant impact on the company’s Condensed Consolidated Financial Statements. On December 30, 2018, the beginning of Snap-on’s 2019 fiscal year, Snap-on adopted ASU No. 2018-02, Income Statement - Reporting Comprehensive Income - Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income (Topic 220), which allows for a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the U.S. Tax Cuts and Jobs Act (the “Tax Act”). The adoption of this ASU resulted in an increase of $45.9 million to Retained Earnings on the company’s Condensed Consolidated Statements of Equity with an offsetting decrease in Accumulated Other Comprehensive Income (Loss). On December 30, 2018, the beginning of Snap-on’s 2019 fiscal year, Snap-on adopted ASU No. 2016-02, Leases (Topic 842), which increases transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. Topic 842 is intended to represent an improvement over previous GAAP, which did not require lease assets and lease liabilities to be recognized for most leases. Topic 842, which supersedes most current lease guidance, affects any entity that enters into a lease with some specified scope exemptions. Snap-on adopted Topic 842 using the modified retrospective approach, using a date of initial application of December 30, 2018. Snap-on elected the package of practical expedients permitted under the standard, which also allowed the company to carry forward historical lease classifications. The company also elected the practical expedient related to treating lease and non-lease components as a single lease component for all equipment leases as well as electing a policy exclusion permitting leases with an original lease term of less than one year to be excluded from the Right-of-Use (“ROU”) assets and lease liabilities. The adoption of this ASU did not have a significant impact on the company’s Condensed Consolidated Financial Statements. See note 15 for further information on leases. The following new accounting pronouncements, and related impacts on adoption, are being evaluated by the company: In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820) - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, which is designed to improve the effectiveness of disclosures by removing, modifying and adding disclosures related to fair value measurements. ASU No. 2018-13 is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years; the ASU allows for early adoption in any interim period after issuance of the update. The adoption of this ASU is not expected to have a significant impact on the company’s consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General Subtopic 715-20 - Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans, which is designed to improve the effectiveness of disclosures by removing and adding disclosures related to defined benefit plans. ASU No. 2018-14 is effective for fiscal years ending after December 15, 2020; the ASU allows for early adoption in any year end after issuance of the update. The adoption of this ASU is not expected to have a significant impact on the company’s consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326), to require the measurement of expected credit losses for financial instruments held at the reporting date based on historical experience, current conditions and reasonable forecasts. The main objective of this ASU is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. ASU No. 2016-13 is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years; the ASU allows for early adoption as of the beginning of an interim or annual reporting period beginning after December 15, 2018. The company is currently assessing the impact this ASU will have on its consolidated financial statements.