Shareholders' Equity (Details 2) (USD $)	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2013
Principal assumptions used in applying the Black-Scholes option pricing model for the awards
Weighted-average grant-date fair value (in dollars per share)	$ 7.86	$ 6.29	$ 7.14
Shares options, additional information
Compensation expenses (in dollars)	$ 983,000	$ 1,496,000	$ 1,481,000
Stock options
Principal assumptions used in applying the Black-Scholes option pricing model for the awards
Dividend yield (as a percent)		0.00%
Expected volatility (as a percent)		47.00%
Risk-free interest rate (as a percent)		3.42%
Expected holding period		8 years 8 months 26 days
Weighted-average grant-date fair value (in dollars per share)		$ 6.29
Stock options, shares
Outstanding at beginning of year (in shares)	1,588,750	1,632,700
Granted (in shares)		230,000
Exercised (in shares)	(69,250)	(273,950)
Forfeited (in shares)	(18,000)
Outstanding at end of year (in shares)	1,501,500	1,588,750	1,632,700
Exercisable at end of year (in shares)	1,249,750	1,160,625
Stock options, Weighted Average Exercise Price
Outstanding at beginning of year (in dollars per share)	$ 9.39	$ 8.03
Granted (in dollars per share)		$ 10.72
Exercised (in dollars per share)	$ 2.60	$ 2.36
Forfeited (in dollars per share)	$ 10.96
Outstanding at end of year (in dollars per share)	$ 9.69	$ 9.39	$ 8.03
Exercisable at end of year (in dollars per share)	$ 9.36	$ 8.68
Weighted Average Remaining Contractual Term (in years)
Outstanding at end of year (in years)	5 years 1 month 6 days	5 years 9 months 18 days
Exercisable at end of year (in years)	4 years 7 months 6 days	4 years 10 months 24 days
Aggregate Intrinsic Value
Outstanding at end of year (in dollars)	3,425,000	1,464,000
Exercisable at end of year (in dollars)	3,266,000	1,464,000
Shares options, additional information
Compensation expenses (in dollars)	746,000	1,437,000	1,481,000
Unamortized compensation cost (in dollars)				467,000
Weighted average period in which unamortized compensation cost is expected to be recognized	1 year 4 months 24 days
Cash received from option exercises (in dollars)	180,000	647,000	41,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	273,000	2,192,000	52,800
Restricted stock
Shares options, additional information
Compensation expenses (in dollars)	237,000	59,000
Unamortized compensation cost (in dollars)				$ 629,000
Weighted average period in which unamortized compensation cost is expected to be recognized	2 years 6 months