Long-Term Debt (Schedule Of Long-Term Debt) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011
Long-Term Debt [Abstract]
Convertible notes payable	$ 300,000		$ 300,000
Bank credit facility - term loans	131,250		138,750
Bank credit facility - revolver loans	180,000		125,000
Principal amount of long-term debt	611,250		563,750
Less unamortized discount	(11,421)		(24,289)
Less unamortized debt issuance costs	(3,522)	(11,400)	(4,654)	(24,300)
Total long-term debt	596,307		534,807
Less current portion	(295,517)		(7,500)
Long-term debt, net of current portion	$ 300,790		$ 527,307