Risk Management and Use of Derivative Financial Instruments - Interest Rate Swap and Caps Summary (Details) € in Thousands, $ in Thousands	Sep. 30, 2018 USD ($) instrument	Sep. 30, 2018 EUR (€) instrument
Derivative Disclosure
Fair value	$ 1,340
Cash Flow Hedging \| Interest rate swap \| USD
Derivative Disclosure
Derivative number of instruments \| instrument	9	9
Notional Amount	$ 86,863
Fair value	$ 1,336
Cash Flow Hedging \| Interest rate cap \| EUR
Derivative Disclosure
Derivative number of instruments \| instrument	1	1
Notional Amount \| €		€ 30,050
Fair value	$ 4

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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- References

No definition available.

+ Details

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959

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- Definition

Fair value as of the balance sheet date of interest rate derivative assets, net of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized on the balance sheet.

+ References

No definition available.

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