CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net income	$ 77,344	$ 53,183
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	23,127	26,093
Share-based compensation	41,704	32,762
Deferred income taxes	(455)	75
Tax effect from share-based payment arrangements	15,704	10,903
Excess tax benefits from share-based payment arrangements	(16,100)	(11,364)
Provision for doubtful accounts, net	1,305	0
Net loss on sales of property and equipment	0	12
Changes in operating assets and liabilities:
Accounts receivable	(3,184)	10,609
Prepaid expenses and other assets	14,306	(11,309)
Accounts payable	(1,635)	2,324
Accrued compensation and employee benefits	2,556	(19,700)
Other liabilities	(1,166)	(6,968)
Deferred revenue	8,119	(220)
Net cash provided by operating activities	161,625	86,400
Cash flows from investing activities:
Purchases of property and equipment	(12,541)	(18,266)
Cash paid for acquisitions, net of cash acquired	(5,683)	(56,992)
Distribution from cost method investees	37	75
Net cash used in investing activities	(18,187)	(75,183)
Cash flows from financing activities:
Proceeds from revolving line of credit	49,000	241,000
Payments on revolving line of credit	(56,000)	(68,000)
Payments on senior notes	0	(71,000)
Proceeds from issuance of treasury stock under employee stock plans	8,356	13,643
Taxes paid related to net share settlement of equity awards	(28,544)	(18,102)
Dividends paid	(1,869)	(1,882)
Repurchases of common stock	(96,121)	(130,719)
Excess tax benefits from share-based payment arrangements	16,100	11,364
Net cash used in financing activities	(109,078)	(23,696)
Effect of exchange rate changes on cash	(2,325)	(8,238)
Increase (decrease) in cash and cash equivalents	32,035	(20,717)
Cash and cash equivalents, beginning of period	86,120	105,075
Cash and cash equivalents, end of period	118,155	84,358
Supplemental disclosures of cash flow information:
Income taxes refunds (payments), net	836	(31,122)
Cash paid for interest	19,143	22,835
Supplemental disclosures of non-cash investing and financing activities:
Purchase of property and equipment included in accounts payable	3,566	733
Unsettled repurchases of common stock	$ 4,351	$ 0