Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a nonrecurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

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Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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Fair Value Measurements (Carrying Amounts and Fair Value of Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 27, 2016	Dec. 29, 2015	Dec. 30, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deferred compensation plan	$ 500	$ 1,500
Net facility impairment charges			$ 980
Level 3 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net facility impairment charges	4,898	7,469
Assets, fair value disclosure, nonrecurring	1,700	4,800
Fair Value, Measurements, Recurring \| Carrying (Reported) Amount, Fair Value Disclosure \| Equities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	11,268	10,385
Fair Value, Measurements, Recurring \| Carrying (Reported) Amount, Fair Value Disclosure \| Equities \| Level 1 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	11,268	10,385
Fair Value, Measurements, Recurring \| Carrying (Reported) Amount, Fair Value Disclosure \| Equities \| Level 2 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	0	0
Fair Value, Measurements, Recurring \| Carrying (Reported) Amount, Fair Value Disclosure \| Equities \| Level 3 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	0	0
Fair Value, Measurements, Recurring \| Carrying (Reported) Amount, Fair Value Disclosure \| Fixed income
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	5,267	3,748
Fair Value, Measurements, Recurring \| Carrying (Reported) Amount, Fair Value Disclosure \| Fixed income \| Level 1 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	0	0
Fair Value, Measurements, Recurring \| Carrying (Reported) Amount, Fair Value Disclosure \| Fixed income \| Level 2 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	5,267	3,748
Fair Value, Measurements, Recurring \| Carrying (Reported) Amount, Fair Value Disclosure \| Fixed income \| Level 3 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	0	0
Fair Value, Measurements, Recurring \| Carrying (Reported) Amount, Fair Value Disclosure \| Money market fund
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	6,662	29,584
Fair Value, Measurements, Recurring \| Carrying (Reported) Amount, Fair Value Disclosure \| Money market fund \| Level 1 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	6,662	0
Fair Value, Measurements, Recurring \| Carrying (Reported) Amount, Fair Value Disclosure \| Money market fund \| Level 2 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	0	29,584
Fair Value, Measurements, Recurring \| Carrying (Reported) Amount, Fair Value Disclosure \| Money market fund \| Level 3 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	$ 0	$ 0