Investments in Marketable Securities and Unconsolidated Entities - Outstanding Borrowings of Unconsolidated Entities (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Sep. 30, 2014
Schedule of Equity Method Investments [Line Items]
Investments in marketable securities and unconsolidated entities	$ 10,372	$ 38,341
Unconsolidated Entities
Schedule of Equity Method Investments [Line Items]
Investments in marketable securities and unconsolidated entities	10,372	13,576
Total equity of unconsolidated entities	36,773	59,336
Total outstanding borrowings of unconsolidated entities	$ 10,537	$ 11,254