Capital Stock (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Share purchases
Aggregate price at which shares of common stock purchased (in dollars)	$ 5,319	$ 5,067	$ 3,110
Additional number of shares authorized to be repurchased	481,261
Common Stock
Share purchases
Shares of common stock purchased	250,763	210,841	184,020
Aggregate price at which shares of common stock purchased (in dollars)	$ 5,319	$ 5,067	$ 3,110
Number of shares of common stock held in treasury	2,000	1,000
Common Stock | Maximum
Share purchases
Shares of common stock authorized to be repurchased	4,500,000
Common Stock | Direct Stock Purchase Plan
Share purchases
Shares registered	1,500,000
Shares purchased	4,291	3,770	3,770
Shares of common stock available for purchase	1,377,444