Stock Based Compensation (Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding and Exercisable) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at end of period (shares)	5,800,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at beginning of period (shares)	4,851,000	4,275,000	4,801,000
Granted (shares)	1,608,000	1,194,000	1,032,000
Exercised (shares)	(857,000)	(524,000)	(1,203,000)
Cancelled/Expired (shares)	(125,000)	(94,000)	(355,000)
Outstanding at end of period (shares)	5,477,000	4,851,000	4,275,000	4,801,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Wieghted-Average Exercise Price, Outstanding at beginning of period	$ 5.57	$ 4.77	$ 4.97
Weighted-Average Exercise Price, Granted	$ 9.91	$ 8.29	$ 4.57
Weighted-Average Exercise Price, Exercised	$ 5.18	$ 4.09	$ 4.39
Weighted-Average Exercise Price, Cancelled/Expired	$ 9.68	$ 12.01	$ 8.17
Wieghted-Average Exercise Price, Outstanding at end of period	$ 6.81	$ 5.57	$ 4.77	$ 4.97
Wieghted-Average Remaining Contractual Term in Years, Outstanding at September 30, 2012 (years)	4 years 4 months 10 days
Aggregate Intrinsic Value, Outstanding at September 30, 2012	$ 14,867
Number of Shares, Exercisable (shares)	3,072,000	2,868,000		2,348,000
Wieghted-Average Exercise Price, Exercisable	$ 5.42	$ 5.31		$ 5.60
Wieghted-Average Remaining Contractual Term in Years, Exercisable (years)	3 years 3 months 11 days	3 years 6 months 4 days		3 years 9 months 22 days
Aggregate Intrinsic Value, Exercisable at September 30, 2012	12,057
Number of Shares, Vested and expected to vest after September 30, 2012 (shares)	5,319,000
Wieghted-Average Exercise Price, Vested and expected to vest after September 30, 2012	$ 6.74
Weighted-Average Remaining Contractual Term in Years, Vested and expected to vest after September 30, 2012 (years)	4 years 3 months 22 days
Aggregate Intrinsic Value, Vested and expected to vest after September 30, 2012	$ 14,777