Variable Interest Entities ("VIEs") (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Unconsolidated VIEs
Variable Interest Entity
Net carrying amount of our investments in nonconsolidated VIEs	$ 352,925	$ 392,150
Consolidated VIEs
Variable Interest Entity
Total assets of our consolidated VIEs, excluding the Operating Partnership	3,561,062	3,638,483
Total liabilities of our consolidated VIEs, excluding the Operating Partnership	$ 1,753,798	$ 1,762,322

The carrying amount of the consolidated Variable Interest Entity's assets included in the reporting entity's statement of financial position.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (bb)
-URI http://asc.fasb.org/extlink&oid=77990344&loc=d3e5710-111685

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- Definition

The carrying amount of the consolidated Variable Interest Entity's liabilities included in the reporting entity's statement of financial position.

+ References

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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

Carrying amount of the assets in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph a
-URI http://asc.fasb.org/extlink&oid=77990344&loc=d3e5728-111685

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