CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net income	$ 250,864	$ 199,193
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	6,178	8,294
Share-based compensation	67,022	56,755
Deferred income taxes	(13,041)	(18,360)
Net gain on marketable securities	(6,727)	(1,681)
Non-cash operating lease costs	6,772	7,613
Provision for doubtful accounts	838	738
Gain (Loss) on Disposition of Assets	0	1,941
Net loss on sales and abandonment of property and equipment	408	24
Changes in operating assets and liabilities:
Accounts receivable	(72,661)	(13,789)
Prepaid expenses and other assets	(12,490)	(17,078)
Accounts payable	(579)	(2,810)
Accrued compensation and employee benefits	(34,170)	(32,318)
Other liabilities	(5,049)	(2,425)
Deferred revenue	5,790	29
Net cash provided by operating activities	193,155	182,244
Cash flows from investing activities:
Purchases of property and equipment	(5,403)	(2,377)
Payments to Develop Software	(5,380)	0
Proceeds from sales of marketable securities	15,571	4,631
Purchases of marketable securities	(16,828)	(8,015)
Cash transferred, net of proceeds, from product line asset sale	0	(6,126)
Net cash used in investing activities	(12,040)	(11,887)
Cash flows from financing activities:
Proceeds from revolving line of credit and term loan	255,000	228,000
Payments on revolving line of credit and term loan	(74,500)	(158,500)
Payments on finance leases	1,400	0
Proceeds from issuance of treasury stock under employee stock plans	14,937	15,217
Taxes paid related to net share settlement of equity awards	(133,786)	(73,672)
Repurchases of common stock	(243,473)	(184,290)
Net cash used in financing activities	(183,222)	(173,245)
Effect of exchange rate changes on cash	996	7,457
Increase (decrease) in cash and cash equivalents	(1,111)	4,569
Cash and cash equivalents, beginning of period	136,778	133,202
Cash and cash equivalents, end of period	135,667	137,771
Supplemental disclosures of cash flow information:
Cash paid for income taxes, net of refunds of $320 and $548 during the six-month periods ended March 31, 2024 and 2023, respectively	53,757	72,800
Cash paid for interest	50,331	46,801
Supplemental disclosures of non-cash investing and financing activities:
Purchase of property and equipment included in accounts payable	439	9
Unsettled repurchases of common stock	7,780	6,981
Finance lease obligations incurred	$ 9,400	$ 0