Effective income tax rate on earnings attributable to Snap-on.

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Tax Cuts And Jobs Act of 2017, Pension Contributions, Income Tax Expense (Benefit)

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Amount of deferred tax liability attributable to taxable temporary differences from undistributed earnings of subsidiary and other recognized entity not within country of domicile. Includes, but is not limited to, other basis differences.

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Amount of income tax expense (benefit) for remeasurement of deferred tax from change in tax rate pursuant to Tax Cuts and Jobs Act.

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Amount of reasonable estimate for income tax expense (benefit) for which accounting for tax effect is incomplete pursuant to Tax Cuts and Jobs Act.

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Amount of reasonable estimate for income tax expense for which accounting for tax effect from transition tax on accumulated earnings of controlled foreign corporation deemed repatriated is incomplete pursuant to Tax Cuts and Jobs Act.

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Amount of income tax expense from transition tax on accumulated earnings of controlled foreign corporation deemed repatriated pursuant to Tax Cuts and Jobs Act.

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The earnings that is allocated to common stock and participating securities to the extent that each security may share in earnings as if all of the earnings for the period had been distributed.

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Income Taxes - Narratve (Detail) - USD ($)	12 Months Ended
Income Taxes - Narratve (Detail) - USD ($)	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Income Tax [Line Items]
Effective income tax rate	23.40%	24.00%	31.10%
Tax Cuts and Jobs Act, income tax expense			$ 7,000,000.0
Tax Cuts and Jobs Act, Transition tax			13,700,000
Provision includes revaluation of deferred tax assets and liabilities, benefit			6,700,000
Tax Cut and Jobs Act, Transition Tax		$ 8,300,000
Additional net tax benefits due to pension contributions and other changes		4,400,000
Valuation allowance	$ 27,800,000	25,100,000	25,200,000
Unrecognized tax benefits	10,300,000	11,100,000	7,700,000	$ 9,400,000
Accrued interest and penalties related to unrecognized tax benefits	1,100,000	800,000	600,000
Interest and penalties related to unrecognized tax benefits	300,000
Increase in unrecognized tax benefits	500,000	2,800,000	1,000,000.0
Undistributed earnings	271,800,000
Undistributed foreign earnings	6,600,000	$ 6,000,000.0	$ 0
Deferred Income Tax Assets
Income Tax [Line Items]
Unrecognized tax benefits	1,200,000
Other Long-Term Liabilities
Income Tax [Line Items]
Unrecognized tax benefits	9,100,000
Accrued interest and penalties related to unrecognized tax benefits	1,100,000
Minimum
Income Tax [Line Items]
Decrease in unrecognized tax benefits	0
Increase in unrecognized tax benefits	0
Maximum
Income Tax [Line Items]
Decrease in unrecognized tax benefits	2,400,000
Increase in unrecognized tax benefits	$ 900,000