Revenue Recognition - Property Management Fees (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Deferred Revenue Disclosure [Abstract]
Property management fee percent based on gross collected rents			3.00%
Property management fee percent based on the cost of construction			5.00%
Aggregate property management fees	$ 11,618	$ 11,626	$ 35,851	$ 33,603