DISCONTINUED OPERATIONS - Cash Flow (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Depreciation and amortization	$ 7,703	$ 6,998	$ 14,568	$ 13,859
Equity-based compensation			9,797	7,746
Non-cash lease expense			1,065	1,162
Increase in non-cash contingent consideration expense from original estimate			(498)	1,758
Expenditures for capitalized software			(4,384)	(4,204)
Discontinued Operations, Held-for-Sale or Disposed of by Sale \| Healthcare RCM Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Depreciation and amortization				1,665
Equity-based compensation				595
Non-cash lease expense				523
Increase in non-cash contingent consideration expense from original estimate	$ 0	$ 1,167	$ 0	1,292
Expenditures for capitalized software				$ (218)

Amount of increase (decrease) in value of liability in contingent consideration arrangement in business combination, including, but not limited to, difference arising upon settlement.

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