Fair Value Measurements (Carrying Amounts and Fair Value of Assets) (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Mar. 26, 2013		Dec. 25, 2012
Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	$ 7,086	[1]	$ 5,833	[1]
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	3,793	[1]	3,144	[1]
Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	3,293	[1]	2,689	[1]
Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	0	[1]	0	[1]
Fixed Income Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	4,892	[1]	4,344	[1]
Fixed Income Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	377	[1]	369	[1]
Fixed Income Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	4,515	[1]	3,975	[1]
Fixed Income Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	0	[1]	0	[1]
Money Market Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	49,700	[2]	17,619	[2]
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	0	[2]	0	[2]
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	49,700	[2]	17,619	[2]
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	$ 0	[2]	$ 0	[2]

[1] These investments relate to the Deferred Compensation Plan and the POWR Plan and are located in the other assets line item on the Consolidated Balance Sheets. The investments categorized as Level 2 in the fair value hierarchy are valued by using available market information which includes quoted market prices for identical or similar assets in non-active markets.

[2] At March 26, 2013 and December 25, 2012 $1.1 million and $0.3 million, respectively, related to the Deferred Compensation Plan and the POWR Plan are located in the other assets line item on the Consolidated Balance Sheets. At March 26, 2013 and December 25, 2012 the remaining $48.6 million and $17.3 million, respectively were short-term in nature and were classified in cash and cash equivalents on the Consolidated Balance Sheets. Money market funds are valued at amortized cost which reflects the market-based fair value.