Earnings per share - Earnings per share computations (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Notes to Financial Statements
Weighted average common shares outstanding during the period - shares used for basic earnings per common share	9,382	9,291	9,341	9,279
Common shares issuable under share based payment plans which are potentially dilutive	100	152	117	174
Common shares used for diluted earnings per common share	9,482	9,443	9,458	9,453
Net income	$ 2,684	$ 2,379	$ 6,451	$ 10,457
Earnings per common share
Basic	$ 0.29	$ 0.26	$ 0.69	$ 1.13
Diluted	$ 0.28	$ 0.25	$ 0.68	$ 1.11