Earnings Per Common Share (Details) (USD $) In Thousands, except Per Share data	3 Months Ended								12 Months Ended
	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Earnings Per Common Share Details [Abstract]
Net Income	$ 10,030	$ 11,390	$ 10,332	$ 10,828	$ 8,798	$ 9,137	$ 7,671	$ 7,834	$ 42,580	$ 33,440	$ 24,905
Weighted Average Number of Shares Outstanding, Basic	12,497	12,484	12,462	12,415	12,318	12,265	12,207	12,173	12,464	12,241	12,088
Effect Of Dilutive Securities [Abstract]
Stock Options And Restricted Stock Diluted Shares									49	154	218
Weighted Average Number of Shares Outstanding, Diluted	12,531	12,526	12,511	12,483	12,437	12,408	12,376	12,356	12,513	12,395	12,306
Basic EPS	$ 0.80	$ 0.91	$ 0.83	$ 0.87	$ 0.71	$ 0.74	$ 0.63	$ 0.64	$ 3.42	$ 2.73	$ 2.06
Diluted EPS	$ 0.80	$ 0.91	$ 0.83	$ 0.87	$ 0.71	$ 0.74	$ 0.62	$ 0.63	$ 3.40	$ 2.70	$ 2.02