Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income (loss)	$ 130,695	$ (27,460)	$ 51,987
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	80,817	77,824	87,408
Amortization of right-of-use lease assets	38,687	0	0
Stock-based compensation	115,149	86,400	82,939
Other non-cash items, net	(3,167)	(4,148)	534
Provision (benefit) from deferred income taxes	(24,641)	1,708	(56,556)
Changes in operating assets and liabilities, excluding the effects of acquisitions:
Accounts receivable	(32,365)	29,446	20,396
Accounts payable and accrued expenses	(5,135)	16,200	5,251
Accrued compensation and benefits	10,282	(12,098)	(6,988)
Deferred revenue	17,046	45,875	56,141
Accrued income taxes	(26,616)	232	10,323
Other current assets and prepaid expenses	36,189	(2,829)	(10,642)
Operating lease liabilities	(11,110)	0	0
Other noncurrent assets and liabilities	(92,023)	73,995	6,959
Net cash provided by operating activities	233,808	285,145	247,752
Cash flows from investing activities:
Additions to property and equipment	(20,196)	(64,411)	(36,041)
Purchases of short- and long-term marketable securities	(33,869)	(33,027)	(24,311)
Proceeds from sales of short- and long-term marketable securities	1,521	1,507	0
Proceeds from maturities of short- and long-term marketable securities	30,521	30,469	18,140
Acquisitions of businesses, net of cash acquired	(483,478)	(86,737)	(3,000)
Purchases of investments	0	(7,500)	(1,000)
Purchase of intangible assets	(11,050)	0	(3,000)
Settlement of net investment hedges	(9,421)	9,675	0
Net cash used in investing activities	(525,972)	(150,024)	(49,212)
Cash flows from financing activities:
Proceeds from issuance of Senior Notes	1,000,000	0	0
Borrowings under credit facility	455,000	205,000	250,000
Repayments of Senior Notes	(500,000)	0	0
Repayments of borrowings under credit facility	(610,125)	(180,000)	(320,000)
Repurchases of common stock	0	(114,994)	(1,100,000)
Proceeds from issuance of common stock	18,382	12,975	1,015,654
Debt issuance costs	(17,107)	0	(2,851)
Contingent consideration	0	(1,575)	(8,275)
Debt early redemption premium	(15,000)	0	0
Payments of withholding taxes in connection with stock-based awards	(33,740)	(44,366)	(45,374)
Net cash provided by (used in) financing activities	297,410	(122,960)	(210,846)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	25	(2,565)	(7,810)
Net change in cash, cash equivalents, and restricted cash	5,271	9,596	(20,116)
Cash, cash equivalents, and restricted cash, beginning of period	270,689	261,093	281,209
Cash, cash equivalents, and restricted cash, end of period	275,960	270,689	261,093
Supplemental disclosure of non-cash financing activities:
Fair value of contingent consideration recorded for acquisition	$ 0	$ 0	$ 2,100