DISCLOSURE OF OFFSETTING ASSETS AND LIABILITIES, COLLATERAL, ENCUMBERED ASSETS, AND REPURCHASE AGREEMENTS, Encumbered Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Sep. 30, 2015
Financial instruments owned, at fair value, pledged to counterparties that:
Had the right to deliver or repledge	$ 326,901	$ 424,668
Did not have the right to deliver or repledge	25,229	94,006
Fair value of securities pledged with a clearing organization	18,900	30,500
Securities reserve deposit required and made	$ 148,900	$ 147,600