Summary of Accounting Policies (Policies)	3 Months Ended
Summary of Accounting Policies (Policies)	Mar. 31, 2018
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 2017 Annual Report on Form 10-K for the fiscal year ended December 30, 2017 (“2017 year end”). The company’s 2018 fiscal first quarter ended on March 31, 2018; the 2017 fiscal first quarter ended on April 1, 2017. The company’s 2018 and 2017 fiscal first quarters each contained 13 weeks of operating results. Certain prior year amounts have been reclassified on the Condensed Consolidated Statements of Earnings to conform to the 2018 presentation following the retrospective adoption of ASU No. 2017-07, Compensation - Retirement Benefits (Topic 715) - Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. “Cost of goods sold” of $0.3 million and “Operating expenses” of $0.4 million in the first quarter of 2017 were reclassified to “Other income (expense) - net”. As a result, previously reported “Cost of goods sold” of $439.1 million is now $438.8 million, “Operating expenses” of $278.5 million is now $278.1 million and “Other income (expense) - net” of $1.7 million of expense is now $2.4 million of expense. Additionally, prior year "Operating earnings" for certain reportable business segments have been restated to reflect these reclassifications. See Note 17 for information on Snap-on’s reportable business segments. 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 31, 2018, and April 1, 2017, 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.
New Accounting Standards	New Accounting Standards The following new accounting pronouncements were adopted in fiscal year 2018: In March 2017, the Financial Accounting Standards Board (the "FASB") issued ASU No. 2017-07, Compensation – Retirement Benefits (Topic 715) – Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, which provides additional guidance on the presentation of net periodic pension and postretirement benefit costs in the income statement and on the components eligible for capitalization. The amendments in this ASU require that an employer report the service cost component of the net periodic benefit costs in the same income statement line item as other compensation costs arising from services rendered by employees during the period. The non-service-cost components of net periodic benefit costs are to be presented in the income statement separately from the service cost components and outside a subtotal of income from operations. The ASU also allows for the capitalization of the service cost components, when applicable (i.e., as a cost of internally manufactured inventory or a self-constructed asset). Snap-on adopted this ASU at the beginning of its 2018 fiscal year, with the changes related to the presentation in the statements of earnings of the service cost and non-service-cost components of net periodic benefit costs applied retrospectively, using the practical expedient permitting the use of the amounts disclosed in pension and other postretirement benefit plan notes as the estimation basis for the presentation of the prior comparative periods. For fiscal 2018 and all comparative periods, the non-service-cost components of net periodic benefit costs are included in “Other income (expense) - net” on the accompanying condensed consolidated statements of earnings. Beginning in fiscal 2018, changes related to the capitalization in assets of the service cost component of net periodic benefit costs were applied prospectively. The adoption of this ASU did not have a significant impact on the company’s Condensed Consolidated Statements of Earnings. In October 2016, the FASB issued ASU No. 2016-16, Income Taxes (Topic 740) – Intra-Entity Transfers of Assets Other Than Inventory. The ASU eliminates the requirement to defer the recognition of current and deferred income taxes for an intra-entity asset transfer until the asset has been sold to an outside party. Under the new guidance, an entity should recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The ASU is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The amendments in this ASU were to be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings at the time of adoption. The adoption of this ASU did not have an impact on the company's consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230), which adds and/or clarifies guidance on the classification of certain cash receipts and payments in the statement of cash flows. The new guidance is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. This ASU is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The adoption of the ASU did not have a significant impact to the designations of operating, investing and financing activities on the company's Condensed Consolidated Statements of Cash Flows. On December 31, 2017, the beginning of Snap-on’s 2018 fiscal year, Snap-on adopted ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. Topic 606 is based on the principle that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Topic 606 also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to fulfill a contract. Snap-on adopted Topic 606 using the modified retrospective approach applied to those contracts that were not completed as of December 31, 2017, which means Topic 606 has been applied to the fiscal 2018 financial statements and disclosures going forward, but that prior period financial statements and disclosures reflect the prior revenue recognition standard. See Note 2 for additional information on revenue recognition. Snap-on’s revenues are primarily from the selling of products that are shipped and billed, services provided to customers and from subscriptions, including software subscriptions. Approximately 90% of net sales are earned at a point in time through ship-and- bill performance obligations. The remaining performance obligations that are recorded over time relate primarily to software subscriptions and to a lesser extent extended warranty and other subscription agreements. Revenues are recognized when control is transferred to customers, in an amount that reflects the consideration Snap-on expects to be entitled to in exchange for those goods and services. Revenue recognition is evaluated through the following five steps: (i) identification of the contract, or contracts, with a customer; (ii) identification of the performance obligations in the contract; (iii) determination of the transaction price; (iv) allocation of the transaction price to the performance obligations in the contract; and (v) recognition of revenue when or as a performance obligation is satisfied. Revenue related to software subscriptions, as well as extended warranty and other subscription agreements, is generally recognized over time on a ratable basis over the contract term beginning on the date that our service is made available to the customer. Contracts with customers may include multiple performance obligations related to sales of hardware, software and software-related services. For these contracts, individual performance obligations are recorded separately if they are distinct. The transaction price, including any discounts, is allocated to each separate performance obligation based on its relative standalone selling price. The standalone selling prices are determined based on the prices charged to customers or by using an expected cost plus margin approach. The amount assigned to the products or services is recognized when the product is delivered and/or when the services are performed. In instances where the product and/or services are performed over an extended period, as is the case with subscription agreements, revenue is generally recognized over time on a ratable basis using a time-based output method applied over the contract term beginning on the date that the service is made available to the customer. These contracts are generally for 12 months but can be for a term up to 60 months. Franchise fee revenue, including nominal, non-refundable initial fees, is recognized upon the granting of a franchise, which is when the company has performed substantially all initial services required by the franchise agreement. Franchise fee revenue also includes ongoing monthly fees (primarily for sales and business training as well as marketing and product promotion programs) that are recognized as the fees are earned. Franchise fee revenue totaled $3.9 million for the three month period ended March 31, 2018. The following new accounting pronouncements, and related impacts on adoption, are being evaluated by the company: In February 2018, the FASB issued 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 Tax Cuts and Jobs Act (the "Tax Act"). ASU No. 2018-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years; the ASU allows for early adoption in any interim period after issuance of the update. The company is currently assessing the impact this ASU will have on its consolidated financial statements. In August 2017, the FASB issued 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. ASU No. 2017-12 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years; the ASU allows for early adoption in any interim period after issuance of the update. The company is currently assessing the impact this ASU will have on its 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. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The ASU is intended to represent an improvement over previous GAAP, which did not require lease assets and lease liabilities to be recognized for most leases. This ASU, which supersedes most current lease guidance, affects any entity that enters into a lease (as that term is defined in the ASU), with some specified scope exemptions. ASU No. 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years; the ASU allows for early adoption as of the beginning of an interim or annual reporting period. The company is currently assessing the impact this ASU will have on its consolidated financial statements.