Earnings Per Share ("EPS") and Cash Dividends - Summary of Basic EPS and Diluted EPS Calculations (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share Diluted [Line Items]
Net income	$ 5,476	$ 8,591	$ 12,982	$ 18,310
Basic shares	13,479	13,302	13,436	13,255
Diluted shares	13,577	13,465	13,568	13,404
Basic EPS	$ 0.41	$ 0.65	$ 0.97	$ 1.38
Diluted EPS	$ 0.40	$ 0.64	$ 0.96	$ 1.37
Stock Options
Earnings Per Share Diluted [Line Items]
Incremental shares from the assumed exercise of outstanding stock options and lapse of restrictions on restricted stock awards	58	104	83	99
Restricted Stock
Earnings Per Share Diluted [Line Items]
Incremental shares from the assumed exercise of outstanding stock options and lapse of restrictions on restricted stock awards	40	59	49	50