Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities:
Net income (loss)	$ 143,769	$ (35,398)	$ 85,424
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Stock-based compensation	48,787	51,305	45,402
Depreciation and amortization	76,551	66,471	62,394
Provision for loss on accounts receivable	213	258	51
(Benefit from) provision for deferred income taxes	(39,714)	104,766	(35,063)
Excess tax benefits realized from stock-based awards	(334)	(1,324)	(5,398)
Other non-cash costs, net	126	32	55
Changes in operating assets and liabilities, excluding the effects of acquisitions:
Accounts receivable	17,308	32,309	(32,334)
Accounts payable and accrued expenses	(4,828)	(8,556)	(58)
Accrued litigation	0	0	(52,129)
Accrued compensation and benefits	11,036	983	(3,788)
Deferred revenue	6,727	14,362	8,195
Accrued income taxes, net of income tax receivable	(15,211)	(4,005)	18,931
Other current assets and prepaid expenses	(9,113)	8,332	(1,826)
Other noncurrent assets	(11,766)	(12,423)	(15,111)
Other noncurrent liabilities	1,132	863	3,953
Net cash provided by operating activities	224,683	217,975	78,698
Cash flows from investing activities:
Additions to property and equipment	(29,328)	(31,413)	(27,817)
Acquisitions of businesses, net of cash acquired	(245,843)	(220)	(280,026)
Other	721	0	0
Net cash used by investing activities	(274,450)	(31,633)	(307,843)
Cash flows from financing activities:
Borrowings under revolving credit facility	0	230,000	250,000
Repayments of borrowings under revolving credit facility	(111,875)	(60,000)	(50,000)
Repurchases of common stock	(74,871)	(34,953)	(54,921)
Proceeds from issuance of common stock	4,884	21,210	24,756
Excess tax benefits realized from stock-based awards	334	1,324	5,398
Payments of withholding taxes in connection with vesting of stock-based awards	(14,996)	(20,967)	(22,520)
Credit facility origination costs	0	(1,951)	(995)
Other	0	0	(1,298)
Net cash (used) provided by financing activities	(196,524)	134,663	150,420
Effect of exchange rate changes on cash and cash equivalents	(1,339)	660	6,350
Net (decrease) increase in cash and cash equivalents	(247,630)	321,665	(72,375)
Cash and cash equivalents, beginning of year	489,543	167,878	240,253
Cash and cash equivalents, end of year	$ 241,913	$ 489,543	$ 167,878