Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 15,167	$ 10,231	$ (18,506)
Other comprehensive income (loss), net of tax:
Unrealized holding gains (losses) on available-for-sale securities arising during the period	235	335	(804)
Reclassification adjustment for realized gains included in net income (loss)	(217)	(142)	(235)
Other comprehensive income (loss)	18	193	(1,039)
Comprehensive income (loss)	$ 15,185	$ 10,424	$ (19,545)