Fair Value Measurements (Fair Value Of Long Term Debt) (Details) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, carrying value		$ 792,719
Unamortized debt discount		(16,511)	$ (20,900)
Term Loan Maturing June 2018 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, carrying value		262,500	277,500
Long-term debt, fair value	[1]	259,547	270,563
Nordea Q5000 Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, carrying value		241,071	0
Long-term debt, fair value	[1]	236,852	0
MARAD Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, carrying value		89,148	94,792
Long-term debt, fair value	[1]	98,036	104,830
Convertible Senior Notes (Matures March 2032) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, carrying value	[2]	200,000	200,000
Long-term debt, fair value	[1],[2]	166,250	222,900
Loan Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, carrying value		792,719	572,292
Long-term debt, fair value	[1]	$ 760,685	$ 598,293

[1] The estimated fair value of the 2032 Notes was determined using Level 1 inputs under the market approach. The fair value of the Term Loan, the Nordea Q5000 Loan and the MARAD Debt was estimated using Level 2 fair value inputs under the market approach. The fair value of the Term Loan, the Nordea Q5000 Loan and the MARAD Debt was determined using a third party evaluation of the remaining average life and outstanding principal balance of the indebtedness as compared to other obligations in the marketplace with similar terms.

[2] Carrying amount excludes the related unamortized debt discount of $16.5 million at September 30, 2015 and $20.9 million at December 31, 2014