Stockholders' Equity (Details) (USD $) Share data in Thousands	12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Class of Stock [Line Items]
Preferred stock, shares authorized	5,000	5,000
Common stock, shares authorized	500,000	500,000
Stock authorized to repurchase	$ 100,000,000
Repurchases of common stock, shares	2,600	3,700	1,200
Repurchases of common stock, value	$ 54,921,000	$ 62,542,000	$ 14,157,000
Series A Junior Participating Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized	500