Significant Accounting Policies - Fair Value Mearsurements (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 26, 2016	Dec. 27, 2015
Measurement of financial assets and liabilities at fair value on a recurring basis
Transfers among levels within the fair value hierarchy	$ 0
Carrying Value
Measurement of financial assets and liabilities at fair value on a recurring basis
Cash surrender value of life insurance policies	19,838	$ 17,916
Interest rate swap liabilities	8,331	2,262
Measured on Recurring Basis \| Level 1
Measurement of financial assets and liabilities at fair value on a recurring basis
Cash surrender value of life insurance policies	19,838	17,916
Measured on Recurring Basis \| Level 2
Measurement of financial assets and liabilities at fair value on a recurring basis
Interest rate swap liabilities	$ 8,331	$ 2,262

Fair value portion of the amount that could be realized under a life insurance contract or contracts owned by the entity, commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash Surrender Value
-URI http://asc.fasb.org/extlink&oid=6507153

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- Definition

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.

+ References

No definition available.

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- Definition

Amount of transfer of financial instrument classified as an asset into (out of) level 3 of the fair value hierarchy.

+ References

No definition available.

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- Definition

Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13433-108611

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