Income Taxes (Components Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2011
Domestic [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards, domestic	$ 8,069	$ 19,483
Credit carryforwards	11,167	10,701
Deferred revenue	28,196	24,612
Stock based compensation	21,347	14,128
Other compensation	4,874	4,026
Other	3,274	1,974
Total deferred tax assets	76,927	74,924
Less: valuation allowance	(145)	(141)
Net deferred tax assets	76,782	74,783
Intangible assets	(10,305)	(13,957)
Property and equipment	(13,463)	(10,526)
Deferred costs	(24,718)	(20,365)
Other	(394)	(1,193)
Total deferred tax liabilities	48,880	46,041
Deferred tax assets (liability), net	27,902	28,742
Foreign [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards, foreign	3,741	2,804
Deferred revenue	1,368	697
Stock based compensation	1,480	1,023
Other	524	199
Total deferred tax assets	7,113	4,723
Less: valuation allowance	(3,073)	(157)
Net deferred tax assets	4,040	4,566
Deferred Tax Liabilities, Goodwill and Intangible Assets, Intangible Assets	3,975	5,048
Deferred costs	(83)	(89)
Other	(506)	(422)
Total deferred tax liabilities	4,564	5,559
Deferred tax assets (liability), net	$ (524)	$ (993)