Borrowings (Schedule Of Long-Term Borrowings) (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended			12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended
	Jun. 28, 2007	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 4.00% Borrowings Due December 7, 2016 [Member]	Dec. 31, 2011 4.00% Borrowings Due December 7, 2016 [Member]	Dec. 31, 2012 4.60% Borrowings Due June 21, 2017 [Member]	Dec. 31, 2011 4.60% Borrowings Due June 21, 2017 [Member]	Dec. 31, 2012 3.97% Borrowings Due December 7, 2017 [Member]	Dec. 31, 2011 3.97% Borrowings Due December 7, 2017 [Member]	Dec. 31, 2012 3.66% Borrowings Due December 26, 2017 [Member]	Dec. 31, 2011 3.66% Borrowings Due December 26, 2017 [Member]	Dec. 31, 2012 3.79% Borrowings Due December 26, 2017 [Member]	Dec. 31, 2011 3.79% Borrowings Due December 26, 2017 [Member]
Maturity Date	Sep. 15, 2037			Dec. 07, 2016		Jun. 21, 2017		Dec. 07, 2017		Dec. 26, 2017		Dec. 26, 2017
Initial Conversion Date				Dec. 07, 2008		Jun. 21, 2008		Dec. 07, 2012		Dec. 26, 2009		Dec. 26, 2010
Interest Rate				4.00%		4.60%		3.97%		3.66%		3.79%
Long-term Debt		$ 26,000	$ 26,000	$ 5,000	$ 5,000	$ 6,000	$ 6,000	$ 5,000	$ 5,000	$ 5,000	$ 5,000	$ 5,000	$ 5,000