Revenue Recognition - Managed Equity REITs (Details) - Managed REITs - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Business Management and Incentive Fees
Business management fees as a percentage of transferred real estate assets			0.50%
Business management fees as a percentage of average invested capital below the threshold limit			0.70%
Maximum threshold amount for calculating the business management fees	$ 250,000		$ 250,000
Business management fees as a percentage of average invested capital above the threshold limit			0.50%
Minimum threshold amount for calculating the business management fees	250,000		$ 250,000
Business management fees as a percent of average market capitalization below the threshold limit			0.70%
Business management fees as a percent of average market capitalization above the threshold limit			0.50%
Aggregate base business management fees	$ 21,010	$ 24,833	$ 72,928	$ 78,640
Contingent incentive business management fee percentage			12.00%
Aggregate incentive business management fees			$ 0	$ 120,094