Income Taxes - Reconciliation of Effective Income Tax Rate to Federal Rate (Detail)		3 Months Ended	12 Months Ended
Jan. 01, 2018	Dec. 29, 2018	Sep. 29, 2018	Sep. 30, 2017	Oct. 01, 2016
Income Tax Disclosure [Abstract]
Federal income tax rate	35.00%	21.00%	24.50%	35.00%	35.00%
State taxes, net of federal benefit			1.90%	1.70%	1.80%
Domestic production activity deduction			(1.40%)	(2.10%)	(1.60%)
Earnings in jurisdictions taxed at rates different from the statutory U.S. federal rate			(1.10%)	(1.60%)	(1.10%)
Tax Act			(11.50%)	0.00%	0.00%
Other, including tax reserves and related interest			(1.10%)	(0.90%)	0.10%
Effective Income Tax Rate, Continuing Operations, Total			11.30%	32.10%	34.20%

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to deduction for qualified production activity.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to statutory income tax expense (benefit) outside of the country of domicile.

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Percentage of the difference, between reported income tax expense (benefit) and the expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, that is attributable to tax exempt income, equity in earnings (loss) of an unconsolidated subsidiary, minority interest income (expense), tax holiday, disposition of a business, disposition of an asset, repatriation of foreign earnings, repatriation of foreign earnings jobs creation act of 2004, change in enacted tax rate, prior year income taxes, change in deferred tax asset valuation allowance, and other adjustments.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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