Variable Interest Entities - Maximum Exposure of LOC Losses (Details) - USD ($) $ in Thousands	Mar. 31, 2015	Sep. 30, 2014	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash collateral and other assets	$ 5,920	$ 9,135	$ 9,941
Expected LOC losses	2,650	4,708	2,460
Accounts payable	759	1,026	1,421
Maximum exposure for LOC losses	19,799	29,502	25,943
Exposure secured by titles to customers' automobiles	$ 5,900	$ 7,800	$ 7,300