NON-CONTROLLING INTEREST - Ownership Interest (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Noncontrolling Interest [Abstract]
Net income attributable to non-controlling interest	$ 5,543		$ (753)	$ 7,518	$ 1,155
Distributions to non-controlling interest holders		$ 283		(347)	(839)
Redemption of common units in i3 Verticals, LLC				(17,070)	(576)
Recapitalization from contribution to i3 Verticals, LLC				5,689	0
Allocation of equity (from) to non-controlling interests				(3,588)	4,960
Net transfers (from) to non-controlling interests				(15,316)	3,545
Change from net income attributable to non-controlling interests and net transfers (from) to non-controlling interests				$ (7,798)	$ 4,700

Amount of Net Income (Loss) attributable to noncontrolling interest.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
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-Name Accounting Standards Codification
-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details

i3 Verticals, Inc. 10-Q