Cash, Cash Equivalents and Marketable Securities (Summary Of The Amortized Costs And Fair Values Of Marketable Securities) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
MARKETABLE SECURITIES, Amortized Cost	$ 27,689	$ 36,392
MARKETABLE SECURITIES, Fair Value	27,707	36,404
MARKETABLE SECURITIES, Gross Unrealized Gains	21	18
MARKETABLE SECURITIES - Gross Unrealized Losses	3	6
Tax-Exempt Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
MARKETABLE SECURITIES, Amortized Cost	15,000	20,813
MARKETABLE SECURITIES, Fair Value	15,018	20,825
MARKETABLE SECURITIES, Gross Unrealized Gains	21	18
MARKETABLE SECURITIES - Gross Unrealized Losses	3	6
Variable Rate Demand Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
MARKETABLE SECURITIES, Amortized Cost	12,689	15,579
MARKETABLE SECURITIES, Fair Value	$ 12,689	$ 15,579