Fair Value Measurements (Carrying Amounts and Fair Value of Assets) (Details) - USD ($) $ in Thousands	Sep. 27, 2016	Dec. 29, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deferred compensation plan	$ 600	$ 1,500
Equities | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	10,846	10,385
Equities | Fair Value, Measurements, Recurring | Level 1 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	10,846	10,385
Equities | Fair Value, Measurements, Recurring | Level 2 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	0	0
Equities | Fair Value, Measurements, Recurring | Level 3 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	0	0
Fixed income | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	5,274	3,748
Fixed income | Fair Value, Measurements, Recurring | Level 1 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	0	0
Fixed income | Fair Value, Measurements, Recurring | Level 2 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	5,274	3,748
Fixed income | Fair Value, Measurements, Recurring | Level 3 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	0	0
Money market fund | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	12,689	29,584
Money market fund | Fair Value, Measurements, Recurring | Level 1 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	0	0
Money market fund | Fair Value, Measurements, Recurring | Level 2 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	12,689	29,584
Money market fund | Fair Value, Measurements, Recurring | Level 3 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	$ 0	$ 0