Stockholders' Equity (Details) (USD $) Share data in Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
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	1,553	2,649	3,717
Repurchases of common stock, value	$ 34,953,000	$ 54,921,000	$ 62,542,000
Series A Junior Participating Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized	500