Segments - Schedule of significant expenses and net income for reportable segment (Details) - USD ($) $ in Thousands		3 Months Ended
		Dec. 31, 2025	Dec. 31, 2024
Segment Reporting Information [Line Items]
Revenue		$ 685,825	$ 565,128
Net income		166,518	82,232
Operating Segments
Segment Reporting Information [Line Items]
Revenue		685,825	565,128
Cost of revenue, adjusted	[1]	103,852	97,584
Operating expenses, adjusted	[2]	272,340	276,214
Other segment items	[3]	143,115	109,098
Net income		$ 166,518	$ 82,232

[1] Cost of revenue, adjusted excludes stock-based compensation and amortization of acquired intangible assets.

[2] Operating expenses, adjusted excludes stock-based compensation, amortization of acquired intangible assets, and acquisition and transaction-related charges.

[3] Other segment items include stock-based compensation; amortization of acquired intangible assets; acquisition and transaction-related charges; Other expense, net; and Provision for income taxes.