Debt (Schedule Of Debt) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Long-term Debt	$ 900,247	$ 967,808
Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility amount outstanding	0	0
8.625% Senior Notes [Member]
Debt Instrument [Line Items]
Senior Notes	600,000	600,000
Unamortized discount	(4,178)	(4,849)
7.50% Senior Notes [Member]
Debt Instrument [Line Items]
Senior Notes	300,000	300,000
Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Unamortized discount	0	(1,093)
4.375% Convertible Senior Notes	$ 4,425	$ 73,750