Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Income Taxes [Line Items]
Corporate income tax rate			21.00%	35.00%	35.00%
Income tax benefit recorded as estimate to the impact of the act		$ 48,160,000	$ 5,575,000	$ 48,160,000
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
Gross amount of unrecognized tax benefits	750,000	1,259,000	750,000	1,259,000	$ 1,754,000	$ 727,000
Unrecognized tax benefits that would impact effective tax rate	800,000		800,000
Unrecognized tax benefit, accrued interest	100,000	$ 100,000	100,000	$ 100,000
Domestic Tax Authority
Income Taxes [Line Items]
Federal net operating loss carryforwards	3,700,000		3,700,000
State and Local Jurisdiction
Income Taxes [Line Items]
State net operating loss carryforwards	6,200,000		6,200,000
Credit carryforwards	4,100,000		$ 4,100,000
Operating loss carryforwards expiration date			Dec. 31, 2037
Unrecognized tax benefits that would impact effective tax rate	$ 200,000		$ 200,000