Income Taxes - Temporary Differences (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 01, 2019	Jan. 02, 2018	Jan. 03, 2017
Deferred tax assets:
Staff member benefits	$ 22,925	$ 22,626
Insurance reserves	15,165	14,027
Accrued rent	10,870	12,523
Deferred income	17,288	11,607
Stock-based compensation	8,628	8,710
Tax credit carryforwards	1,880	2,308
Other	1,265	738
Subtotal	78,021	72,539
Less: Valuation allowance	(792)	(455)
Total	77,229	72,084
Deferred tax liabilities:
Property and equipment	(107,513)	(111,324)
Prepaid expenses	(7,929)	(9,120)
Inventory	(6,893)	(6,724)
Other	(5,420)	(2,132)
Total	(127,755)	(129,300)
Net deferred tax liability	(50,526)	(57,216)
Reconciliation of beginning and ending amount of our uncertain tax positions
Balance at beginning of year	843	829	$ 1,067
Additions related to current period tax positions	104	168	139
Reductions related to settlements with taxing authorities and lapses of statutes of limitations	(117)	(154)	(377)
Balance at end of year	830	843	$ 829
Accrued interest and penalties related with uncertain tax positions	200	100
Decrease in uncertain tax positions during the next twelve months based on the lapses of statutes of limitations for certain jurisdictions	0
State
Reconciliation of beginning and ending amount of our uncertain tax positions
Tax credit carryforwards	2,400	2,900
Tax credit carryforward valuation allowance	800	$ 500
Foreign Tax Authority [Member]
Reconciliation of beginning and ending amount of our uncertain tax positions
Tax credit carryforwards	$ 700