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, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Investment in unconsolidated entities	$ 3,726		$ 3,726		$ 4,035
Total equity of unconsolidated entities	4,500		4,500		10,113
Total outstanding borrowings of unconsolidated entities	12,506		12,506		$ 12,266
Equity in income of unconsolidated entities	$ 81	$ 256	$ 17	$ 155