Fair Value Measurements (Carrying Amounts and Fair Value of Assets) (Details) (USD $)	Jun. 25, 2013		Dec. 25, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deferred compensation plan	$ 300,000
Cash and cash equivalents fair value disclosure	64,300,000		17,300,000
Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	7,965,000		5,833,000
Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	7,965,000	[1]	5,833,000	[1]
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	4,973,000	[1]	3,144,000	[1]
Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	2,992,000	[1]	2,689,000	[1]
Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [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	4,705,000		4,344,000
Fixed Income Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	4,705,000	[1]	4,344,000	[1]
Fixed Income Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	1,328,000	[1]	369,000	[1]
Fixed Income Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	3,377,000	[1]	3,975,000	[1]
Fixed Income Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [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	64,586,000		17,619,000
Money Market Funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	64,586,000	[2]	17,619,000	[2]
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [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, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value disclosure	64,586,000	[2]	17,619,000	[2]
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [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 June 25, 2013 and December 25, 2012, $0.3 million related to the Deferred Compensation Plan and the POWR Plan is located in the other assets line item on the Consolidated Balance Sheets. At June 25, 2013 and December 25, 2012 the remaining $64.3 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.