Investment in Unconsolidated Real Estate Ventures - Summary of Results of Operations of Real Estate Ventures with Interests (Parenthetical) (Details) - Unconsolidated Real Estate Ventures [Member]	Sep. 30, 2018	Sep. 30, 2017
Minimum [Member]
Schedule Of Equity Method Investments [Line Items]
Ownership percentage	25.00%	20.00%
Maximum [Member]
Schedule Of Equity Method Investments [Line Items]
Ownership percentage	70.00%	70.00%

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant