Stockholders' Equity (Equity Narrative) (Details) (USD $)	12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Purchase of treasury stock	$ 9,700,000	$ 8,703,000	$ 866,000
2010 Authorization [Member]
Authorized repurchase amount	200,000,000
Repurchase period in years	3
Purchase of treasury stock	6,837,000	2,998,000
Purchase of treasury stock, number of shares	208,000	108,000
2007 Authorization [Member]
Authorized repurchase amount	200,000,000
Repurchase period in years	3
Purchase of treasury stock		$ 1,515,000	$ 0
Purchase of treasury stock, number of shares		55,000	0