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EQUITY-BASED COMPENSATION - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Sep. 30, 2025
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	$ 5,136	$ 4,879	$ 14,933	$ 12,030
Weighted-average grant date fair value (in USD per share)			$ 12.41
Outstanding at end of period (in shares)	8,790,566		8,790,566		7,881,236
Options exercisable at end of period (in shares)	6,765,894		6,765,894
Unrecognized compensation expense related to unvested options at end of period	$ 18,042		$ 18,042
Fair value of stock options that vested	187		5,024
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	2,414	1,610	$ 5,615	5,435
Period for recognition of unrecognized compensation cost (in years)			3 years 4 months 24 days
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	$ 2,722	3,269	$ 9,318	6,595
Period for recognition of unrecognized compensation cost (in years)			2 years 6 months
Granted (in USD per share)	$ 24.01		$ 24.01
Cost not yet recognized, amount	$ 18,210		$ 18,210
Vested in period, fair value	$ 455		$ 10,148
Discontinued Operations, Held-for-Sale or Disposed of by Sale \| Healthcare RCM Business
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense		$ 2,517		$ 3,112