ACQUISITIONS - Narrative (Details) $ in Thousands			12 Months Ended
	Feb. 07, 2025 USD ($) global_market destination broker	Nov. 05, 2024 USD ($)	Aug. 31, 2025 USD ($)	Aug. 31, 2024 USD ($)	Aug. 31, 2023 USD ($)
Business Combination [Line Items]
Purchase price			$ 348,255	$ 0	$ 23,593
Contingent consideration			24,126	4,193
Goodwill			$ 1,284,708	$ 1,011,129	$ 1,004,736
Liquid Holdings, LLC ("LiquidityBook")
Business Combination [Line Items]
Purchase price	$ 243,200
Contingent consideration	$ 11,900
Trading solutions, number of brokers | broker	200
Trading solutions, number of destinations | destination	1,600
Trading solutions, number of global markets | global_market	80
Goodwill	$ 164,787
Platform Group Limited ("Irwin")
Business Combination [Line Items]
Purchase price		$ 120,200
Contingent consideration		9,600
Goodwill		$ 91,376