Condensed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 2,459	$ 4,102	$ 6,089	$ 8,350
Other comprehensive (loss) income, net of tax:
Unrealized holding gains on available-for-sale securities arising during the period	49	78	16	316
Reclassification adjustment for realized gains included in net income	(84)	(228)	(84)	(229)
Other comprehensive (loss) income	(35)	(150)	(68)	87
Comprehensive income	$ 2,424	$ 3,952	$ 6,021	$ 8,437