Consolidated Statements of Changes in Stockholders Equity (USD $) In Thousands	Total	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Total stockholders equity at Sep. 30, 2011		$ 2,867,585	$ 4,965	$ 4,082,978	$ 4,055,664	$ (50,141)	$ (5,225,881)
Net income	718,986	718,986			718,986
Total other comprehensive income (loss)	17,484	17,484				17,484
Cash dividends, $0.52 per share, $0.84 per share, and $0.94 per share, respectively, for fiscal years ended September 30, 2012, 2013 and 2014		(132,760)			(132,760)
Exercise of stock options		89,521	45	89,476
Excess tax benefit from exercise of stock options		25,703		25,703
Share-based compensation expense		26,645		26,645
Common stock purchases for employee stock purchase plan		(299)		(299)
Warrants	0
Treasury stock retirement		0	(2,388)	(1,972,030)	(3,371,467)		5,345,885
Purchases of common stock		(1,154,208)					(1,154,208)
Employee tax withholdings related to restricted share vesting		(3,815)					(3,815)
Other		0	3	(3)
Total stockholders equity at Sep. 30, 2012		2,454,842	2,625	2,252,470	1,270,423	(32,657)	(1,038,019)
Net income	433,707	433,707			433,707
Total other comprehensive income (loss)	(2,826)	(2,826)				(2,826)
Cash dividends, $0.52 per share, $0.84 per share, and $0.94 per share, respectively, for fiscal years ended September 30, 2012, 2013 and 2014		(195,716)			(195,716)
Exercise of stock options		114,491	50	114,441
Excess tax benefit from exercise of stock options		41,222		41,222
Share-based compensation expense		36,751		36,751
Settlement of accelerated stock repurchase agreement		(10,312)		(10,312)
Common stock purchases for employee stock purchase plan		(260)		(260)
Warrants	90,055	90,055		90,055
Purchases of capped call options		(163,372)		(163,372)
Purchases of common stock		(473,864)					(473,864)
Employee tax withholdings related to restricted share vesting		(4,973)					(4,973)
Other		0	3	(3)
Total stockholders equity at Sep. 30, 2013	2,319,745	2,319,745	2,678	2,360,992	1,508,414	(35,483)	(1,516,856)
Net income	276,484	276,484			276,484
Total other comprehensive income (loss)	(16,563)	(16,563)				(16,563)
Cash dividends, $0.52 per share, $0.84 per share, and $0.94 per share, respectively, for fiscal years ended September 30, 2012, 2013 and 2014		(214,469)			(214,469)
Exercise of stock options		81,565	30	81,535
Excess tax benefit from exercise of stock options		46,341		46,341
Share-based compensation expense		43,107		43,107
Common stock purchases for employee stock purchase plan		(206)		(206)
Warrants	422,739	422,739		422,739
Purchases of capped call options		(205,320)		(205,320)
Purchases of common stock		(789,927)					(789,927)
Employee tax withholdings related to restricted share vesting		(6,597)					(6,597)
Other		0	3	(3)
Total stockholders equity at Sep. 30, 2014	$ 1,956,899	$ 1,956,899	$ 2,711	$ 2,749,185	$ 1,570,429	$ (52,046)	$ (2,313,380)