Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The number of derivative instruments of a particular group held by the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5579245-113959

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- Definition

Fair value as of the balance sheet date of all foreign currency derivatives designated as cash flow hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (a),(b),(c)(1)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624163-113959

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- Details

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Risk Management and Use of Derivative Financial Instruments - Foreign Currency Derivatives Details (Details) € in Thousands, kr in Thousands, $ in Thousands	Mar. 31, 2018 EUR (€) instrument	Mar. 31, 2018 NOK (kr) instrument	Mar. 31, 2018 USD ($) instrument
Designated as Hedging Instrument \| Foreign currency forward contracts and collars
Derivative
Fair value			$ (3,036)
Designated as Hedging Instrument \| Derivatives in Cash Flow Hedging Relationships \| Foreign currency collars \| Euro
Derivative
Number of Instruments \| instrument	50	50	50
Notional Amount \| €	€ 32,720
Fair value			$ (4,029)
Designated as Hedging Instrument \| Derivatives in Cash Flow Hedging Relationships \| Foreign currency forward contracts and collars \| Euro
Derivative
Number of Instruments \| instrument	21	21	21
Notional Amount \| €	€ 8,134
Fair value			$ 1,189
Designated as Hedging Instrument \| Derivatives in Cash Flow Hedging Relationships \| Foreign currency forward contracts and collars \| NOK
Derivative
Number of Instruments \| instrument	15	15	15
Notional Amount \| kr		kr 23,532
Fair value			$ 542
Designated as Hedging Instrument \| Derivatives in Cash Flow Hedging Relationships \| Foreign currency collars \| NOK
Derivative
Number of Instruments \| instrument	25	25	25
Notional Amount \| kr		kr 51,790
Fair value			$ (298)
Designated as Hedging Instrument \| Net Investment Hedging \| Foreign currency collars \| NOK
Derivative
Number of Instruments \| instrument	3	3	3
Notional Amount \| kr		kr 16,750
Fair value			$ (35)
Designated as Hedging Instrument \| Net Investment Hedging \| Foreign currency forward contracts and collars \| NOK
Derivative
Number of Instruments \| instrument	2	2	2
Notional Amount \| kr		kr 4,504
Fair value			$ 38
Derivatives Not Designated as Hedging Instruments \| Foreign currency collars \| Euro
Derivative
Number of Instruments \| instrument	2	2	2
Notional Amount \| €	€ 3,000
Fair value			$ (443)