Long-Term Debt (Schedule Of Company's Borrowings) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 7.375% Senior Notes [Member]	Dec. 31, 2012 7.375% Senior Notes [Member]	Dec. 31, 2013 Three Point Zero Percentage Convertible Notes [Member]	Nov. 13, 2013 Three Point Zero Percentage Convertible Notes [Member]	Dec. 31, 2012 Three Point Zero Percentage Convertible Notes [Member]	Dec. 31, 2013 Two Point Five Percentage Convertible Notes [Member]	Dec. 31, 2012 Two Point Five Percentage Convertible Notes [Member]	Dec. 11, 2012 Two Point Five Percentage Convertible Notes [Member]	Dec. 31, 2013 Title XI Bonds [Member]	Dec. 31, 2012 Title XI Bonds [Member]	Dec. 31, 2013 Other Debt Obligations [Member]	Dec. 31, 2012 Other Debt Obligations [Member]
Debt Instrument [Line Items]
Convertible Debt					$ 230,000,000	$ 181,500,000	$ 0	$ 350,000,000	$ 350,000,000	$ 300,400,000
Senior Notes, Noncurrent			233,500,000	233,500,000
Long-term Debt	834,118,000	655,309,000									85,217,000	90,733,000	80,563,000	64,007,000
Long-term Debt, Gross	979,280,000	738,240,000
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	45,323,000	21,920,000
Debt Instrument, Unamortized Discount	$ (99,839,000)	$ (61,011,000)	$ (1,041,777)		$ (47,770,257)			$ (40,442,031)			$ (9,265,586)		$ (728,339)