Debt Instrument, Covenant Description, Maximum Leverage Ratio

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Debt Instrument, Periodic Payment On New Borrowings

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Debt Instrument, Restrictive Covenants, Maximum Annual Payment For Other Restricted Payments

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Debt Instrument, Restrictive Covenants, Maximum Annual Payment For Stock Option Plans, Employment Agreements and Incentive Plans

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Debt Instrument, Restrictive Covenants, Maximum Annual Redemption, Repurchase, Acquired Equity Interests

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Debt Instrument, Restrictive Covenants, Maximum Annual Repurchase or Redemption of Qualified Entity Interests

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The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of the required periodic payments applied to principal.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Nominal or face amount used to calculate payments on the derivative asset.

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The effective portion of gain reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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Fixed interest rate that will be received or paid upon exercise of the interest rate swaption contract.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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The net amount of operating interest income (expense).

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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The effective interest rate during the reporting period.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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The carrying value as of the balance sheet date of the noncurrent portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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The net cash inflow or cash outflow from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with either short term or long term maturity that is collateralized (backed by pledge, mortgage or other lien in the entity's assets).

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Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

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Current Credit Agreements - Additional Information (Details)		12 Months Ended
	Dec. 11, 2014 USD ($)	Dec. 25, 2019 USD ($)	Dec. 26, 2018 USD ($)	Dec. 27, 2017 USD ($)
Debt Instrument [Line Items]
Unrealized gains arising during the period from interest rate swap		$ 430,000	$ 0
Reclassifications of gains into net income		(84,000)	0
Proceeds from (Repayments of) Lines of Credit		23,000,000	(20,000,000)
Repayments of Lines of Credit		19,000,000	33,000,000	$ 19,000,000
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months		0
Interest Income (Expense), Net		$ (3,687,000)	(3,502,000)	(3,278,000)
Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate		3.20%
Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate		6.00%
Federal Funds Rate
Debt Instrument [Line Items]
Debt instrument basis percentage		0.50%
LIBOR
Debt Instrument [Line Items]
Debt instrument basis percentage		1.00%
LIBOR \| Minimum
Debt Instrument [Line Items]
Debt instrument basis percentage		1.25%
LIBOR \| Maximum
Debt Instrument [Line Items]
Debt instrument basis percentage		2.25%
Base Rate \| Minimum
Debt Instrument [Line Items]
Debt instrument basis percentage		0.25%
Base Rate \| Maximum
Debt Instrument [Line Items]
Debt instrument basis percentage		1.25%
Senior Secured Revolving Credit Facility
Debt Instrument [Line Items]
Principal payments prior to maturity		$ 0
Credit Agreement Two Thousand Fourteen [Member]
Debt Instrument [Line Items]
Interest Expense, Debt			$ 3,000,000	$ 2,700,000
Debt instrument, interest rate			4.00%
Credit Agreement Two Thousand Fourteen [Member] \| Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate			3.30%
Credit Agreement Two Thousand Fourteen [Member] \| Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate			4.00%
Credit Agreement Two Thousand Fourteen [Member] \| Senior Secured Revolving Credit Facility
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment On New Borrowings			$ 13,000,000
2018 Credit Agreement
Debt Instrument [Line Items]
Interest Expense, Debt		$ 3,100,000
Senior secured revolving facility	$ 150,000,000
Senior secured revolving facility term	5 years
Debt instrument, interest rate		3.20%
Letters of credit outstanding		$ 8,400,000
Revolving line of credit		97,000,000
Amount of borrowings available		44,600,000
2018 Credit Agreement \| Letter of Credit
Debt Instrument [Line Items]
Sub limit of revolving facility	$ 15,000,000
2018 Credit Agreement \| Swing Line Loans
Debt Instrument [Line Items]
Sub limit of revolving facility	$ 15,000,000
2018 Credit Agreement \| Senior Secured Revolving Credit Facility
Debt Instrument [Line Items]
Debt Instrument, Restrictive Covenants, Maximum Annual Repurchase or Redemption of Qualified Entity Interests		1,000,000
Debt Instrument, Restrictive Covenants, Maximum Annual Redemption, Repurchase, Acquired Equity Interests		500,000
Debt Instrument, Restrictive Covenants, Maximum Annual Payment For Stock Option Plans, Employment Agreements and Incentive Plans		2,500,000
Debt Instrument, Restrictive Covenants, Maximum Annual Payment For Other Restricted Payments		$ 5,000,000
Debt Instrument, Covenant Description, Maximum Leverage Ratio		4.25
Interest Rate Swap [Member]
Debt Instrument [Line Items]
Interest Expense, Debt		$ 461,000	0
Reclassifications of gains into net income		(84,000)	0
Derivative Asset, Notional Amount		$ 40,000,000
Derivative, Swaption Interest Rate		2.81%
Interest Income (Expense), Net		$ 377,000	$ 0