Stock Based Compensation (Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding and Exercisable) (Details) (Options, USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended
	Mar. 31, 2013
Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at September 30, 2012	5,477
Granted	1,000
Exercised	(275)
Cancelled/Expired	(40)
Outstanding at March 31, 2013	6,162
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding at September 30, 2012	$ 6.81
Granted	$ 9.14
Exercised	$ 4.79
Cancelled/Expired	$ 9.56
Outstanding at March 31, 2013	$ 7.26
Aggregate Intrinsic Value, options exercised	$ 1,175
Wieghted-Average Remaining Contractual Term in Years, Outstanding at March 31, 2013 (years)	4 years 5 months 5 days
Aggregate Intrinsic Value, Outstanding at March 31, 2013	13,359
Number of Shares, Exercisable at March 31, 2013 (shares)	3,389
Wieghted-Average Exercise Price, Exercisable at March 31, 2013	$ 5.82
Wieghted-Average Remaining Contractual Term in Years, Exercisable at March 31, 2013 (years)	3 years 3 months 11 days
Aggregate Intrinsic Value, Exercisable at March 31, 2013	11,854
Number of Shares, Vested and expected to vest after March 31, 2013 (shares)	5,977
Wieghted-Average Exercise Price, Vested and expected to vest after March 31, 2013	$ 7.19
Weighted-Average Remaining Contractual Term in Years, Vested and expected to vest after March 31, 2013 (years)	4 years 4 months 17 days
Aggregate Intrinsic Value, Vested and expected to vest after March 31, 2013	$ 13,318