CONSOLIDATED STATEMENTS OF COMMON STOCK EQUITY (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Premium on Common Stock [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Treasury Stock and Other [Member]	Retained Earnings [Member]
Beginning Balance at Sep. 30, 2010	$ 725,483	$ 109,713	$ 251,147	$ (12,007)	$ (110,385)	$ 487,015
Beginning Balance (shares) at Sep. 30, 2010		41,174,000
Net income	101,299					101,299
Other comprehensive (loss) income	1,403			1,403
Common stock issued under stock plans (shares)		621,000
Common stock issued under stock plans	24,128	545	12,370		11,213
Tax benefits from stock plans	2,007		2,007
Cash dividend declared	(59,552)					(59,552)
Treasury stock and other (shares)		(373,000)
Treasury stock and other	(18,511)				(18,511)
Ending Balance at Sep. 30, 2011	776,257	110,258	265,524	(10,604)	(117,683)	528,762
Ending Balance (shares) at Sep. 30, 2011		41,422,000
Net income	92,879					92,879
Other comprehensive (loss) income	(167)			(167)
Common stock issued under stock plans (shares)		445,000
Common stock issued under stock plans	18,641	698	6,262		11,681
Tax benefits from stock plans	780		780
Cash dividend declared	(63,976)					(63,976)
Treasury stock and other (shares)		(247,000)
Treasury stock and other	(10,549)				(10,549)
Ending Balance at Sep. 30, 2012	813,865	110,956	272,566	(10,771)	(116,551)	557,665
Ending Balance (shares) at Sep. 30, 2012	41,619,633	41,620,000
Net income	114,809					114,809
Other comprehensive (loss) income	9,150			9,150
Common stock issued under stock plans (shares)		958,000
Common stock issued under stock plans	39,996	1,607	25,455		12,934
Tax benefits from stock plans	2,175		2,175
Cash dividend declared	(67,590)					(67,590)
Treasury stock and other (shares)		(616,000)
Treasury stock and other	(25,021)				(25,021)
Ending Balance at Sep. 30, 2013	$ 887,384	$ 112,563	$ 300,196	$ (1,621)	$ (128,638)	$ 604,884
Ending Balance (shares) at Sep. 30, 2013	41,961,534	41,962,000