Segment Information - Narrative (Details) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019 USD ($) segment	Jun. 30, 2019 USD ($) segment	Dec. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| segment	3	3
Other assets, net	$ 296,916	$ 296,916	$ 264,994
Third-Party Real Estate Services Segment
Segment Reporting Information [Line Items]
Other assets, net	$ 35,100	$ 35,100	$ 38,600

Amount of assets classified as other.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(17))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(10))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(10))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant