Income Taxes	9 Months Ended
Sep. 29, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Snap-on’s effective income tax rate on earnings attributable to Snap-on was 24.6% and 30.5% in the first nine months of 2018 and 2017, respectively. The effective tax rate for 2018 includes the net tax benefits attributable to the Tax Act, which was signed into law on December 22, 2017. The Tax Act made broad and complex changes to the U.S. tax code, including, but not limited to, (i) reducing the U.S. federal corporate tax rate from 35 percent to 21 percent; and (ii) requiring companies to pay a one-time transition tax on certain unremitted earnings of foreign subsidiaries. The Tax Act also established new tax laws that affect 2018, including, but not limited to: (i) the reduction of the U.S. federal corporate tax rate discussed above; (ii) a general elimination of U.S. federal income taxes on dividends from foreign subsidiaries; (iii) a new provision designed to tax global intangible low-taxed income (“GILTI”); (iv) the repeal of the domestic production activity deductions; (v) limitations on the deductibility of certain executive compensation; (vi) limitations on the use of foreign tax credits to reduce the U.S. income tax liability; and (vii) a new provision that allows a domestic corporation an immediate deduction for a portion of its foreign derived intangible income (“FDII”). The Securities and Exchange Commission staff issued Staff Accounting Bulletin (“SAB”) 118, which provides guidance on accounting for the tax effects of the Tax Act. SAB 118 provides a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete the related accounting under ASC 740, Accounting for Income Taxes. In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the Tax Act for which the accounting under ASC 740 is complete. To the extent that a company’s accounting for a certain income tax effect of the Tax Act is incomplete, but it is able to determine a reasonable estimate, it must record a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the Tax Act. The company’s accounting for the certain elements of the Tax Act was incomplete as of the period ended December 30, 2017, and remains incomplete as of September 29, 2018. However, the company was able to make reasonable estimates of the effects and, therefore, recorded provisional estimates for these items. In connection with its initial analysis of the impact of the Tax Act, the company recorded a provisional discrete net tax expense of $7.0 million in the period ended December 30, 2017. This provisional estimate consists of a net expense of $13.7 million for the one-time transition tax and a net benefit of $6.7 million related to revaluation of deferred tax assets and liabilities, caused by the new lower corporate tax rate. To determine the transition tax, the company must determine the amount of post-1986 accumulated earnings and profits of the relevant subsidiaries, as well as the amount of non-U.S. income taxes paid on such earnings. While the company was able to make a reasonable estimate of the transition tax, it is continuing to gather additional information to more precisely compute the final amount. Likewise, while the company was able to make a reasonable estimate of the impact of the reduction to the corporate tax rate, its rate may be affected by other analyses related to the Tax Act, including, but not limited to, the state tax effect of adjustments made to federal temporary differences. Due to the complexity of the new GILTI tax rules, the company is continuing to evaluate this provision of the Tax Act and the application of ASC 740. Under GAAP, the company is allowed to make an accounting policy choice to either (i) treat taxes due on future U.S. inclusions in taxable income related to GILTI as a current-period expense when incurred (the “period cost method”); or (ii) factor in such amounts into a company’s measurement of its deferred taxes (the “deferred method”). The company’s selection of an accounting policy with respect to the new GILTI tax rules is dependent on additional analysis and potential future modifications to existing structures, which are not currently known. The company has not made a policy decision regarding whether to record deferred taxes on GILTI. The company will continue to analyze the full effects of the Tax Act on its consolidated financial statements. During the first nine months of 2018, the Internal Revenue Service issued new guidance affecting the computation of the company’s 2017 federal income tax liability. As a result of this new guidance and additional analysis of the impacts of the Tax Act, the company revised its prior estimates and recorded $1.8 million and $3.9 million of net tax expense related to the Tax Act during the respective three and nine months ended September 29, 2018. The ultimate impact of the Tax Act may differ from the current estimates, possibly materially, due to changes in interpretations and assumptions the company has made, future guidance that may be issued and actions the company may take as a result of the law. Snap-on and its subsidiaries file income tax returns in the United States and in various state, local and foreign jurisdictions. It is reasonably possible that certain unrecognized tax benefits may either be settled with taxing authorities or the statutes of limitations for such items may lapse within the next 12 months, causing Snap-on’s gross unrecognized tax benefits to decrease by a range of zero to $0.8 million. Over the next 12 months, Snap-on anticipates taking certain tax positions on various tax returns for which the related tax benefit does not meet the recognition threshold. Accordingly, Snap-on’s gross unrecognized tax benefits may increase by a range of zero to $1.5 million over the next 12 months for uncertain tax positions expected to be taken in future tax filings.

Income Taxes

Snap-on’s effective income tax rate on earnings attributable to Snap-on was 24.6% and 30.5% in the first nine months of 2018 and 2017, respectively. The effective tax rate for 2018 includes the net tax benefits attributable to the Tax Act, which was signed into law on December 22, 2017.

The Tax Act made broad and complex changes to the U.S. tax code, including, but not limited to, (i) reducing the U.S. federal corporate tax rate from 35 percent to 21 percent; and (ii) requiring companies to pay a one-time transition tax on certain unremitted earnings of foreign subsidiaries.

The Tax Act also established new tax laws that affect 2018, including, but not limited to: (i) the reduction of the U.S. federal corporate tax rate discussed above; (ii) a general elimination of U.S. federal income taxes on dividends from foreign subsidiaries; (iii) a new provision designed to tax global intangible low-taxed income (“GILTI”); (iv) the repeal of the domestic production activity deductions; (v) limitations on the deductibility of certain executive compensation; (vi) limitations on the use of foreign tax credits to reduce the U.S. income tax liability; and (vii) a new provision that allows a domestic corporation an immediate deduction for a portion of its foreign derived intangible income (“FDII”).

The Securities and Exchange Commission staff issued Staff Accounting Bulletin (“SAB”) 118, which provides guidance on accounting for the tax effects of the Tax Act. SAB 118 provides a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete the related accounting under ASC 740, Accounting for Income Taxes. In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the Tax Act for which the accounting under ASC 740 is complete. To the extent that a company’s accounting for a certain income tax effect of the Tax Act is incomplete, but it is able to determine a reasonable estimate, it must record a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the Tax Act.

The company’s accounting for the certain elements of the Tax Act was incomplete as of the period ended December 30, 2017, and remains incomplete as of September 29, 2018. However, the company was able to make reasonable estimates of the effects and, therefore, recorded provisional estimates for these items. In connection with its initial analysis of the impact of the Tax Act, the company recorded a provisional discrete net tax expense of $7.0 million in the period ended December 30, 2017. This provisional estimate consists of a net expense of $13.7 million for the one-time transition tax and a net benefit of $6.7 million related to revaluation of deferred tax assets and liabilities, caused by the new lower corporate tax rate. To determine the transition tax, the company must determine the amount of post-1986 accumulated earnings and profits of the relevant subsidiaries, as well as the amount of non-U.S. income taxes paid on such earnings. While the company was able to make a reasonable estimate of the transition tax, it is continuing to gather additional information to more precisely compute the final amount. Likewise, while the company was able to make a reasonable estimate of the impact of the reduction to the corporate tax rate, its rate may be affected by other analyses related to the Tax Act, including, but not limited to, the state tax effect of adjustments made to federal temporary differences. Due to the complexity of the new GILTI tax rules, the company is continuing to evaluate this provision of the Tax Act and the application of ASC 740. Under GAAP, the company is allowed to make an accounting policy choice to either (i) treat taxes due on future U.S. inclusions in taxable income related to GILTI as a current-period expense when incurred (the “period cost method”); or (ii) factor in such amounts into a company’s measurement of its deferred taxes (the “deferred method”). The company’s selection of an accounting policy with respect to the new GILTI tax rules is dependent on additional analysis and potential future modifications to existing structures, which are not currently known. The company has not made a policy decision regarding whether to record deferred taxes on GILTI. The company will continue to analyze the full effects of the Tax Act on its consolidated financial statements.

During the first nine months of 2018, the Internal Revenue Service issued new guidance affecting the computation of the company’s 2017 federal income tax liability. As a result of this new guidance and additional analysis of the impacts of the Tax Act, the company revised its prior estimates and recorded $1.8 million and $3.9 million of net tax expense related to the Tax Act during the respective three and nine months ended September 29, 2018. The ultimate impact of the Tax Act may differ from the current estimates, possibly materially, due to changes in interpretations and assumptions the company has made, future guidance that may be issued and actions the company may take as a result of the law.

Snap-on and its subsidiaries file income tax returns in the United States and in various state, local and foreign jurisdictions. It is reasonably possible that certain unrecognized tax benefits may either be settled with taxing authorities or the statutes of limitations for such items may lapse within the next 12 months, causing Snap-on’s gross unrecognized tax benefits to decrease by a range of zero to $0.8 million. Over the next 12 months, Snap-on anticipates taking certain tax positions on various tax returns for which the related tax benefit does not meet the recognition threshold. Accordingly, Snap-on’s gross unrecognized tax benefits may increase by a range of zero to $1.5 million over the next 12 months for uncertain tax positions expected to be taken in future tax filings.