CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	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	20,596		20,596
Issuance of treasury stock under employee stock plans	(4,139)	8	(28,510)	24,363
Issuance of treasury stock under employee stock plans (in shares)		705
Tax effect from share-based payment arrangements	9,306		9,306
Repurchases of common stock	(100,713)	(14)		(100,699)
Repurchases of common stock (shares)		(1,384)
Dividends paid	(1,260)				(1,260)
Net income	33,277				33,277
Foreign currency translation adjustments	(30,519)					(30,519)
Ending Balance at Mar. 31, 2015	$ 381,162	$ 314	$ 1,130,709	$ (2,012,431)	$ 1,316,278	$ (53,708)
Ending Balance (in shares) at Mar. 31, 2015		31,368