Hedging Activities And Financial Instruments (Schedule Of Carrying Amounts And Fair Values Of Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Nov. 30, 2011 Senior Convertible Notes Due December 15, 2016 [Member]	Dec. 31, 2013 Carrying Amount [Member]	Dec. 31, 2012 Carrying Amount [Member]	Dec. 31, 2013 Fair Value [Member]	Dec. 31, 2012 Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Grand Junction note receivable, Fair Value					$ 1,891		$ 1,711
5.5% convertible notes	$ 12,035	$ 86,981		$ 11,416	$ 80,531	$ 12,035	$ 86,981
Interest rate on debt	5.50%		5.50%