Related Party Transactions - Narrative (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2018 USD ($) property	Dec. 31, 2017 USD ($)
Related Party Transaction [Line Items]
Related party expense	$ 317	$ 302
Related party - general and administrative	116	81
Real Property Management Real Estate Brokerage And Construction Supervision Services | Majestic Property Management Corporation
Related Party Transaction [Line Items]
Related party expense	14	9
Shared Services Agreement | Gould Investors Limited Partnership
Related Party Transaction [Line Items]
Related party - general and administrative	116	81
Affiliated Entity
Related Party Transaction [Line Items]
Related party expense	$ 986	818
Number of investments | property	3
Affiliated Entity | Payment of Acquisition Fee
Related Party Transaction [Line Items]
Related party expense	$ 378	$ 230