Variable Interest Entities - Narrative (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Unconsolidated VIEs
Variable Interest Entities
Net carrying amount of our investments in unconsolidated VIEs	$ 213,719,000	$ 257,882,000
Consolidated VIEs
Variable Interest Entities
Variable interest entity, consolidated, carrying amount, assets	4,601,771,000	4,445,436,000
Variable interest entity, consolidated, carrying amount, liabilities	$ 2,381,310,000	$ 2,533,753,000

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (bb)
-URI http://asc.fasb.org/extlink&oid=108788376&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.

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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

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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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 4
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-URI http://asc.fasb.org/extlink&oid=108788376&loc=d3e5728-111685

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