Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net income (loss)	$ 160,194	$ 143,769	$ (35,398)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Stock-based compensation	50,889	48,787	51,305
Depreciation and amortization	77,307	76,551	66,471
(Benefit from) provision for deferred income taxes	(19,946)	(39,714)	104,766
Excess tax benefits realized from stock-based awards	(10,428)	(334)	(1,324)
Other non-cash costs, net	(760)	339	290
Changes in operating assets and liabilities, excluding the effects of acquisitions:
Accounts receivable	7,554	17,308	32,309
Accounts payable and accrued expenses	(436)	(4,828)	(8,556)
Accrued compensation and benefits	8,974	11,036	983
Deferred revenue	24,998	6,727	14,362
Accrued income taxes, net of income tax receivable	19,134	(15,211)	(4,005)
Other current assets and prepaid expenses	4,417	(9,113)	8,332
Other noncurrent assets	(17,345)	(10,634)	(11,560)
Net cash provided by operating activities	304,552	224,683	217,975
Cash flows from investing activities:
Additions to property and equipment	(25,275)	(29,328)	(31,413)
Acquisitions of businesses, net of cash acquired	(323,525)	(245,843)	(220)
Other	0	721	0
Net cash used by investing activities	(348,800)	(274,450)	(31,633)
Cash flows from financing activities:
Borrowings under revolving credit facility	1,386,250	0	230,000
Repayments of borrowings under revolving credit facility	(1,032,500)	(111,875)	(60,000)
Repurchases of common stock	(224,915)	(74,871)	(34,953)
Proceeds from issuance of common stock	877	4,884	21,210
Excess tax benefits realized from stock-based awards	10,428	334	1,324
Payments of withholding taxes in connection with vesting of stock-based awards	(26,857)	(14,996)	(20,967)
Credit facility origination costs	(7,930)	0	(1,951)
Net cash provided (used) by financing activities	105,353	(196,524)	134,663
Effect of exchange rate changes on cash and cash equivalents	(9,364)	(1,339)	660
Net increase (decrease) in cash and cash equivalents	51,741	(247,630)	321,665
Cash and cash equivalents, beginning of year	241,913	489,543	167,878
Cash and cash equivalents, end of year	$ 293,654	$ 241,913	$ 489,543