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Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 30, 2017
Income Taxes
Remeasurement of deferred tax balances					$ 0.3
Federal statutory rate (as a percent)					21.00%
Amount of provisional income tax		$ 0.2					$ 3.6
Adjustment to provisional amounts recorded at December 30, 2017			$ 0.1
Effective tax rate (as a percent)	20.90%			41.70%	24.10%	38.00%	22.70%

X

- Definition

Amount of reasonable estimate for income tax expense (benefit) for remeasurement of deferred tax from change in tax rate pursuant to Tax Cuts and Jobs Act of 2017 for which accounting for tax effect is incomplete.

+ References

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- Definition

Amount of reasonable estimate for income tax expense (benefit) from effect of Tax Cuts and Jobs Act of 2017 for which accounting for tax effect is incomplete.

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Amount of income tax expense (benefit) for measurement period adjustment from accounting for tax effect pursuant to Tax Cuts and Jobs Act of 2017.

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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