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, 2009	$ 689,726	$ 109,386	$ 249,219	$ (10,052)	$ (84,598)	$ 425,771
Beginning Balance (shares) at Sep. 30, 2009	41,586,000
Net income	117,457					117,457
Other comprehensive (loss) income	(1,955)			(1,955)
Common stock issued under stock plans (shares)	289,000
Common stock issued under stock plans	7,672	327	1,602		5,743
Tax benefits from stock plans	326		326
Cash dividend declared	(56,213)					(56,213)
Treasury stock and other (shares)	(701,000)
Treasury stock and other	(31,530)				(31,530)
Ending Balance at Sep. 30, 2010	725,483	109,713	251,147	(12,007)	(110,385)	487,015
Ending 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	41,421,786
Net income	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