Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]
Beginning balance at Sep. 30, 2011	$ 140,852	$ 877	$ 74,490	$ (153)	$ 65,638
Beginning balance, shares at Sep. 30, 2011		17,531,000
Net income	10,231				10,231
Other comprehensive income, net of tax	193			193
Issuance of common stock	271	1	270
Issuance of common stock, shares		26,000
Common stock repurchased	(54,991)	(145)	(54,846)
Common stock repurchased, shares	(2,894,253)	(2,894,000)
Common stock options exercised, net	73	1	72
Common stock options exercised, net, shares	11,379	10,000
Purchase of common stock to pay employee taxes	(236)	(1)	(235)
Purchase of common stock to pay employee taxes, shares		(16,000)
Excess tax benefit from stock-based compensation plans	(4,138)		(4,138)
Stock-based compensation	2,733		2,733
Ending balance at Sep. 30, 2012	94,988	733	18,346	40	75,869
Ending balance, shares at Sep. 30, 2012		14,657,000
Net income	15,167				15,167
Other comprehensive income, net of tax	18			18
Issuance of common stock	275	1	274
Issuance of common stock, shares		20,000
Common stock repurchased	(18,809)	(40)	(18,769)
Common stock repurchased, shares	(795,643)	(796,000)
Common stock options exercised, net	144	1	143
Common stock options exercised, net, shares	10,273	10,000
Purchase of common stock to pay employee taxes	(41)		(41)
Excess tax benefit from stock-based compensation plans	(477)		(477)
Stock-based compensation	2,552		2,552
Ending balance at Sep. 30, 2013	93,817	695	2,028	58	91,036
Ending balance, shares at Sep. 30, 2013		13,891,000
Net income	12,031				12,031
Other comprehensive income, net of tax	1,470			1,470
Issuance of common stock	269	8	261
Issuance of common stock, shares		163,000
Common stock repurchased	(11,541)	(25)	(2,330)		(9,186)
Common stock repurchased, shares	(485,777)	(485,000)
Common stock options exercised, net	243	2	241
Common stock options exercised, net, shares	190,434	38,000
Purchase of common stock to pay employee taxes	(1,111)		(1,111)
Excess tax benefit from stock-based compensation plans	236		236
Stock-based compensation	3,337		3,337
Ending balance at Sep. 30, 2014	$ 98,751	$ 680	$ 2,662	$ 1,528	$ 93,881
Ending balance, shares at Sep. 30, 2014		13,607,000