Investments in Unconsolidated Entities - Outstanding Borrowings of Unconsolidated Entities and Equity in Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Sep. 30, 2019
Equity Method Investments and Joint Ventures [Abstract]
Investment in unconsolidated entities	$ 4,040		$ 4,040		$ 3,962
Total equity of unconsolidated entities	6,679		6,679		9,969
Total outstanding borrowings of unconsolidated entities	12,614		12,614		$ 12,658
Equity in income of unconsolidated entities	$ 147	$ 81	$ 134	$ 17