Long-Term Debt and Capital Lease Obligations (Details Textual) - USD ($)	1 Months Ended	12 Months Ended
	Mar. 29, 2018	Dec. 27, 2018	Dec. 28, 2017	Dec. 29, 2016	Mar. 01, 2018	Jan. 28, 2018
Senior Notes, Noncurrent		$ 118,000,000	$ 129,143,000
Line of Credit Facility, Commitment Fee Percentage		0.20%
Line of Credit Facility, Remaining Borrowing Capacity		$ 141,000,000
Interest Paid, Excluding Capitalized Interest, Operating Activities		12,655,000	11,453,000	$ 9,105,000
Derivative, Amount of Hedged Item					$ 50,000,000
Interest Expense		13,079,000	12,100,000	$ 9,176,000
Digital Systems [Member]
Commitment Minimum Lease Payments		6,163,000
Obligation To Be Reduced In Next 12 Months		3,927,000
Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation		40,647,000	34,471,000
Capital Leases, Balance Sheet, Assets by Major Class, Net		45,510,000	45,510,000
Furniture and Fixtures [Member]
Capital Leased Assets, Gross		1,712,000	1,712,000
Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation		499,000	255,000
Building and Building Improvements [Member]
Capital Leased Assets, Gross		25,306,000	25,648,000
Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation		4,183,000	$ 2,300,000
Senior Notes [Member]
Senior Notes, Noncurrent		$ 118,000,000
Long-term Debt, Weighted Average Interest Rate, at Point in Time		4.53%	4.70%
Additional capital leases [Member]
Capital Leased Assets, Gross		$ 104,000
Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation		$ 3,000
Minimum [Member] | Senior Notes [Member]
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		4.02%
Maximum [Member] | Senior Notes [Member]
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		6.55%
Revolving Credit Facility [Member]
Long-term Line of Credit		$ 79,000,000
Debt Instrument, Interest Rate, Effective Percentage		3.46%	2.67%
Credit Agreement [Member]
Line of Credit Facility, Maximum Borrowing Capacity		$ 225,000,000
Interest Rate Swap [Member]
Derivative, Fixed Interest Rate						0.96%
Interest Expense		$ 13,000
Interest Rate Swap Agreements One [Member]
Derivative, Fixed Interest Rate	2.559%
Derivative, Notional Amount	$ 25,000,000
Debt Instrument, Maturity Date	Mar. 01, 2021
Debt Instrument, Interest Rate, Basis for Effective Rate		one-month LIBOR 2.375%
Interest Rate Swap Agreements Two [Member]
Derivative, Fixed Interest Rate		2.687%
Derivative, Notional Amount					$ 25,000,000
Debt Instrument, Maturity Date	Mar. 01, 2023
Debt Instrument, Interest Rate, Basis for Effective Rate		one-month LIBOR 2.375%
Interest Rate Fair Value Hedge Liability at Fair Value		$ 205,000
Mortgage Notes [Member]
Debt, Weighted Average Interest Rate		4.66%	4.22%
Mortgage Notes [Member] | Minimum [Member]
Interest Rate of Unsecured Term Note		3.00%
Mortgage Notes [Member] | Maximum [Member]
Interest Rate of Unsecured Term Note		5.31%