Stock Based Compensation (Details 2) (USD $)	3 Months Ended		9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Tax Impact of Stock-Based Compensation
Excess tax benefits, classified as financing cash flows			$ 686,530
Stock options
Stock Based Compensation
Granted - options (in shares)	0	0	0	0
Stock options, shares
Outstanding at the beginning of the period (in shares)			1,501,500	1,588,750
Exercised (in shares)			(165,250)	(69,250)
Forfeited (in shares)			(21,750)	(3,750)
Outstanding at the end of the period (in shares)	1,314,500	1,515,750	1,314,500	1,515,750
Exercisable at the end of the period (in shares)	1,193,000	1,256,500	1,193,000	1,256,500
Stock options, Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)			$ 9.69	$ 9.39
Exercised (in dollars per share)			$ 4.89	$ 2.60
Forfeited (in dollars per share)			$ 11.64	$ 10.86
Outstanding at the end of period (in dollars per share)	$ 10.26	$ 9.69	$ 10.26	$ 9.69
Exercisable at the end of the period (in shares)	$ 10.16	$ 9.37	$ 10.16	$ 9.37
Stock options, Weighted Average Remaining Contractual Life
Outstanding at the end of the period			4 years 8 months 12 days	5 years 3 months 18 days
Exercisable at the end of the period			4 years 6 months	4 years 9 months 18 days
Stock options, Aggregate Intrinsic Value
Outstanding at the end of the period (in dollars)	5,896,000	2,516,000	5,896,000	2,516,000
Exercisable at the end of the period (in dollars)	5,471,000	2,511,000	5,471,000	2,511,000
Stock options, additional information
Compensation expense (in dollars)	55,000	137,000	262,000	612,000
Unrecognized compensation cost (in dollars)	191,000		191,000
Unamortized cost is expected to be recognized over a weighted-average period			1 year 1 month 6 days
Proceeds from exercise of stock options			808,000	180,000
Intrinsic value of shares exercised (in dollars)			$ 1,153,000	$ 273,000