Income Taxes - Additional Information (Detail) - USD ($)		12 Months Ended
	Jul. 30, 2014	Dec. 27, 2017	Dec. 28, 2016	Dec. 30, 2015
Investments, Owned, Federal Income Tax Note [Line Items]
Valuation allowance released		$ 4,306,000	$ 3,311,000
Increase in valuation allowance		1,000,000	400,000	$ 2,900,000
Percentage of cash savings in taxes realized as a result of utilizing net operating losses payable to pre-IPO stockholders	85.00%
Charge relating to present value of total expected TRA payments		22,000,000		41,400,000
TRA tax expense		(5,600,000)	400,000	200,000
Payments to pre-IPO stockholders under TRA		11,109,000	3,236,000	0
Deferred tax asset credit		12,722,000	11,982,000
Change in tax rate, decrease in deferred tax asset		12,100,000
Change in tax rate, decrease in deferred tax liability		13,500,000
Net benefit to deferred income tax expense		$ 1,440,000	0	0
Operating loss carryforward, expiration		expire beginning in 2030 and 2025, respectively.
State enterprise zone credits, expiration year		2023
Alternative minimum tax credits		$ 900,000
Unrecognized tax benefits		0	0	0
Unrecognized tax benefits interest accrued		0	0	0
Unrecognized tax benefits penalties accrued		0	$ 0	$ 0
Federal
Investments, Owned, Federal Income Tax Note [Line Items]
Net operating loss carryforwards		55,800,000
State and Local Jurisdiction
Investments, Owned, Federal Income Tax Note [Line Items]
Net operating loss carryforwards		20,100,000
Enterprise Zone | State and Local Jurisdiction
Investments, Owned, Federal Income Tax Note [Line Items]
Tax credits carry forward		10,900,000
WOTC | Federal
Investments, Owned, Federal Income Tax Note [Line Items]
Tax credits carry forward		800,000
California | Enterprise Zone
Investments, Owned, Federal Income Tax Note [Line Items]
Deferred tax asset credit		$ 5,400,000