Stock-Based Compensation Plans (Tables) - Summary of Stock Activity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Dec. 31, 2013 Years	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options outstanding at October 1, 2013	414,590
Options granted	31,790
Options exercised	14,396
Options outstanding at December 31, 2013	431,984
Options outstanding weighted average exercise price-beginning balance	$ 20.40
Options outstanding weighted average exercise price - Granted	$ 41.39
Options outstanding weighted average exercise price - Exercised	$ 12.71
Options outstanding weighted average exercise price - Ending balance	$ 22.20
Options outstanding weighted average remaining term	4.5	4.2
Options outstanding weighted average grant date fair value - beginning balance	$ 3,668
Options granted weighted average grant date fair value	545
Options exercised weighted average grant date fair value	89
Options outstanding weighted average grant date fair value - ending balance	4,124
Options exercisable at December 31, 2013	344,830
Options exerciseable weighted average exercise price	$ 20.24
Options exerciseable weighted average remaining term	3.5
Options exerciseable weighted average grant date fair value	2,992
Options vested during three months ended December 31, 2013	28,348
Options vested weighted average grant date fair value	$ 322