Amount 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 increase (decrease) in the income tax rates.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=84176650&loc=d3e32059-109318

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

Name:	us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended				9 Months Ended
	Oct. 06, 2018	Jul. 14, 2018	Dec. 30, 2017	Oct. 07, 2017	Oct. 06, 2018	Oct. 07, 2017
Income Tax Disclosure [Abstract]
Effective tax rate	22.50%			40.60%	20.10%	32.10%
Corporate income tax rate	21.00%			35.00%	21.00%	35.00%
Income tax benefit recorded as estimate to the impact of the act			$ 48,200,000
Adjustments in discrete tax benefit		$ 5,600,000
Adjustments in reduction to federal income tax payable		16,400,000
Increase to federal deferred tax liabilities		$ 10,800,000
Adjustments to provisional estimate					$ 0