Derivative Contracts - Summary of Derivatives (Details) - Interest Rate Swap - Derivatives Designated as Cash Flow Hedges - Cash Flow Hedging $ in Thousands	Jun. 30, 2019 USD ($) instrument
Derivative [Line Items]
Number of Interest Rate Swaps \| instrument	36
Notional	$ 4,484,800
Percent of notional amount related to the Fund	100.00%
Unconsolidated Funds
Derivative [Line Items]
Number of Interest Rate Swaps \| instrument	4
Notional	$ 510,000
Percent of notional amount related to the Fund	100.00%
Forward swap
Derivative [Line Items]
Notional	$ 177,400

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

Equity Method Investment, Summarized Financial Information, Percentage Of Notional Amount Of Derivative

+ References

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- Definition

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+ References

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- Definition

Number of interest rate derivative instruments held by the entity at the reporting date.

+ 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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