Fair Value Measurements (Fair Value Of Long Term Debt) (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, carrying value		$ 812,004
Unamortized debt discount		(17,992)	$ (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		270,000	277,500
Long-term debt, fair value	[1]	265,106	270,563
Nordea Term Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, carrying value		250,000	0
Long-term debt, fair value	[1]	242,031	0
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]	191,624	222,900
MARAD Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, carrying value		92,004	94,792
Long-term debt, fair value	[1]	103,494	104,830
Loan Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, carrying value		812,004	572,292
Long-term debt, fair value	[1]	$ 802,255	$ 598,293

[1] The estimated fair value of the 2032 Notes was determined using Level 1 inputs using the market approach. The fair value of the Term Loan, the Nordea Term 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 Term 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 $18.0 million at June 30, 2015 and $20.9 million at December 31, 2014