Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Mar. 31, 2012
Debt Instrument [Line Items]
Carrying Value	$ 776,291
Unamortized debt discount	(14,963)
Total debt	761,328	$ 551,372
Less current maturities	(71,640)	(28,144)
Long-term debt	689,688	523,228
Term Loan Maturing June 2018 [Member]
Debt Instrument [Line Items]
Carrying Value	255,000	277,500
Unamortized debt discount	0
Less current maturities	(30,000)
Long-term debt	225,000
Convertible Senior Notes 2032 [Member]
Debt Instrument [Line Items]
Carrying Value	200,000	200,000	$ 200,000
Unamortized debt discount	(14,963)	(20,920)	$ (35,400)
Less current maturities	0
Long-term debt	185,037
MARAD Debt 2027 [Member]
Debt Instrument [Line Items]
Carrying Value	89,148	94,792
Unamortized debt discount	0
Less current maturities	(5,926)
Long-term debt	83,222
Nordea Q5000 Loan 2020 [Member]
Debt Instrument [Line Items]
Carrying Value	232,143	$ 0
Unamortized debt discount	0
Less current maturities	(35,714)
Long-term debt	$ 196,429

Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20
-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
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The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
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-Subparagraph (SX 210.9-03.16)
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-Section S99
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Amount of long-term debt, after unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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