Real Estate - Properties Held for Sale - Additional Information (Details) - Fund IV $ in Millions	Sep. 30, 2019 USD ($) property	Jun. 30, 2019 USD ($) property
Business Acquisition [Line Items]
Number of properties held-for-sale \| property	1	1
Properties held-for-sale \| $	$ 2.9	$ 6.3

Carrying amount as of the balance sheet date of investments in land and buildings held for sale, excluding real estate considered to be inventory of the entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(f))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Name:	us-gaap_RealEstateHeldforsale
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant