Approximate forecasted cost of building vessels.

No definition available.

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- Definition

The number of shipyards that were used in agreements.

+ References

No definition available.

+ Details

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- Definition

Count on the vessel which are expected to operate.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
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- Definition

Count of vessels which are under construction.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
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- Definition

The designation of funds furnished by a borrower to a lender to assure future payments of the borrower's real estate taxes and insurance obligations with respect to a mortgaged property. Escrow deposits may be made for a variety of other purposes such as earnest money and contingent payments. This element excludes replacement reserves which are an escrow separately provided for within the US GAAP taxonomy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.10)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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- Definition

The aggregate amount of write-downs for impairments recognized during the period for long-lived assets held for abandonment, exchange or sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 15

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2611-110228

+ Details

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Balance Type:	debit
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- Definition

The net cash inflow or outflow for the increase (decrease) associated with funds that are not available for withdrawal or use (such as funds held in escrow) and are associated with underlying transactions that are classified as investing activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

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Balance Type:	credit
Period Type:	duration

- Definition

Amount of interest capitalized during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Allowance for Funds Used during Construction

-URI http://asc.fasb.org/extlink&oid=6504829

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

+ Details

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Balance Type:	debit
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Note 2 - Vessel Acquisitions and Dispositions (Details Textual) (USD $)	3 Months Ended		12 Months Ended	3 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended
	Mar. 15, 2015	Mar. 15, 2014	Dec. 31, 2012	Sep. 30, 2011	Dec. 31, 2014	Apr. 30, 2014	Dec. 31, 2011
Interest Costs Capitalized	$ 1,200,000us-gaap_InterestCostsCapitalized	$ 2,700,000us-gaap_InterestCostsCapitalized
Escrow Deposit					3,683,000us-gaap_EscrowDeposit
Thoma Sea [Member]
Number of Vessels Under Construction			2
Increase (Decrease) in Restricted Cash			52,400,000
Escrow Deposit					3,700,000
North Sea [Member]
Impairment of Long-Lived Assets to be Disposed of					1,500,000
Number of Ship Yards used in Agreements				3
Additional PSV [Member]
Number of Ship Yards used in Agreements				1
Additional PSV [Member] \| North Sea [Member]
Estimated Cost Of Building Vessels						60,000,000
Large Platform Supply Vessel [Member]
Number of Vessels Under Construction				6
Platform Supply Vessel[ Member] \| Americas [Member]
Number of Vessels Expected to Operate			4
Estimated Cost Of Building Vessels			168,000,000
Platform Supply Vessel[ Member] \| BAE Systems [Member]
Number of Vessels Under Construction			2
Platform Supply Vessel[ Member] \| North Sea [Member]
Number of Vessels Expected to Operate							7
Estimated Cost Of Building Vessels							$ 288,000,000