Stock-Based Compensation Plans (Tables) - Summary of Stock Activity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended
	Jun. 30, 2013 Years	Sep. 30, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options outstanding at October 1, 2012	481,210
Options granted	46,180
Options exercised	100,800
Options outstanding at June 30, 2013	426,590
Options outstanding weighted average exercise price-beginning balance	$ 17.52
Options outstanding weighted average exercise price - Granted	$ 26.20
Options outstanding weighted average exercise price - Exercised	$ 10.61
Options outstanding weighted average exercise price - Ending balance	$ 20.10
Options outstanding weighted average remaining term	4.3	3.8
Options outstanding weighted average grant date fair value - beginning balance	$ 3,782
Options granted weighted average grant date fair value	489
Options exercised weighted average grant date fair value	542
Options outstanding weighted average grant date fair value - ending balance	3,729
Options exercisable at June 30, 2013	338,078
Options exerciseable weighted average exercise price	$ 18.63
Options exerciseable weighted average remaining term	3.3
Options exerciseable weighted average grant date fair value	2,769
Options vested during nine months ended June 30, 2013	28,112
Options vested weighted average grant date fair value	$ 275