DISCONTINUED OPERATIONS - Cash Flow (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Mar. 31, 2024
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Depreciation and amortization	$ 7,840	$ 7,193	$ 15,524	$ 14,247
Equity-based compensation			7,746	12,285
Adjustments to loss (gain) on sale of Merchant Services Business			657
Non-cash lease expense			1,162	2,349
Expenditures for property and equipment			(972)	(1,537)
Expenditures for capitalized software			(4,204)	(6,106)
Purchases of merchant portfolios and residual buyouts			0	(4,214)
Discontinued Operations, Held-for-Sale or Disposed of by Sale \| Merchant Services Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Depreciation and amortization			0	5,561
Equity-based compensation			0	1,905
Amortization of capitalized customer acquisition costs			0	430
Adjustments to loss (gain) on sale of Merchant Services Business			657	0
Non-cash lease expense			0	536
Expenditures for property and equipment			0	(386)
Expenditures for capitalized software			0	(414)
Purchases of merchant portfolios and residual buyouts			$ 0	$ (4,214)

Amortization of Capitalized Customer Acquisition Costs

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- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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- Definition

Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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- Definition

Amount of periodic reduction over lease term of carrying amount of right-of-use asset from operating lease.

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- Definition

The cash outflow associated with the development, modification or acquisition of software programs or applications for internal use (that is, not to be sold, leased or otherwise marketed to others) that qualify for capitalization.

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- Definition

The cash outflow to acquire asset without physical form usually arising from contractual or other legal rights, excluding goodwill.

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The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

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- Definition

Amount of noncash expense for share-based payment arrangement.

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