CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) - 9 months ended Jun. 30, 2015 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Paid-in-Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning Balance at Sep. 30, 2014	$ 454,614	$ 320	$ 1,129,317	$ (1,936,095)	$ 1,284,261	$ (23,189)
Beginning Balance (in shares) at Sep. 30, 2014		32,047
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	32,762		32,762
Issuance of treasury stock under employee stock plans	(4,459)	$ 8	(32,214)	27,747
Issuance of treasury stock under employee stock plans (in shares)		801
Tax effect from share-based payment arrangements	10,903		10,903
Repurchases of common stock	(130,719)	$ (17)		(130,702)
Repurchases of common stock (shares)		(1,711)
Dividends paid	(1,882)				(1,882)
Net income	53,183				53,183
Foreign currency translation adjustments	(17,740)					(17,740)
Ending Balance at Jun. 30, 2015	$ 396,662	$ 311	$ 1,140,768	$ (2,039,050)	$ 1,335,562	$ (40,929)
Ending Balance (in shares) at Jun. 30, 2015		31,137