Investments in Marketable Securities and Unconsolidated Entities - Outstanding Borrowings of Unconsolidated Entities (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Sep. 30, 2014
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated entities and marketable securities	$ 11,407	$ 38,341
Unconsolidated Entities
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated entities and marketable securities	11,407	13,576
Total equity of unconsolidated entities	40,226	59,336
Total outstanding borrowings of unconsolidated entities	$ 11,834	$ 11,254