Capital Stock (Details) $ / shares in Units, $ in Thousands			12 Months Ended
	Dec. 11, 2014 USD ($)	Dec. 11, 2013 USD ($)	Sep. 30, 2015 USD ($) item $ / shares shares	Sep. 30, 2014 USD ($) item $ / shares shares	Sep. 30, 2013 USD ($) $ / shares shares	Jan. 28, 2013 shares
Capital Stock
Number of authorized classes of stock | item			2	2
Common stock, par value (in dollars per share) | $ / shares			$ 0.01	$ 0.01
Par value of preferred stock (in dollars per share) | $ / shares			$ 0.01	$ 0.01
Capital Stock
Fair value of non-cash stock awards granted | $			$ 504	$ 775
Shares of common stock available for issuance			0
Number of Options
Outstanding at the beginning of the period (in shares)			32,500	42,500	218,000
Exercised (in shares)			(32,500)	(10,000)	(175,500)
Outstanding at the end of the period (in shares)			0	32,500	42,500
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share) | $ / shares			$ 14.22	$ 13.59	$ 12.66
Exercised (in dollars per share) | $ / shares			$ 14.22	11.53	12.44
Outstanding at the end of the period (in dollars per share) | $ / shares				$ 14.22	$ 13.59
Aggregate Option Price
Outstanding at the beginning of the period (in dollars) | $			$ 462	$ 577	$ 2,760
Exercised (in dollars) | $			$ (462)	(115)	(2,183)
Outstanding at the end of the period (in dollars) | $				$ 462	$ 577
1998 Stock Incentive Plan
Capital Stock
Term of award				10 years
Shares of common stock reserved for issuance			1,050,000
1998 Stock Incentive Plan | Minimum
Capital Stock
Award vesting period			2 years
1998 Stock Incentive Plan | Maximum
Capital Stock
Award vesting period			4 years
1998 Stock Incentive Plan | Stock options
Capital Stock
Options issued, outstanding and exercisable (in shares)			0
1998 Non-Employee Director Stock Option Plan
Capital Stock
Award vesting period			3 years
Term of award				10 years
Shares of common stock reserved for issuance			150,000
2013 Plan
Capital Stock
Shares of common stock reserved for issuance						800,000
Shares of common stock issued				24,827	31,788
Fair value of non-cash stock awards granted | $	$ 504	$ 775
Shares of common stock available for issuance			743,385