FAIR VALUE MEASUREMENTS - Fair value on a recurring basis (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
6.00%/8.00% Cash/PIK Toggle Senior Secured Exchangeable Notes due 2030
Corporate Borrowings:
Bifurcated embedded derivative	$ 5.5	$ 12.6
New exchangeable notes
Corporate Borrowings:
Bifurcated embedded derivative	62.2	$ 131.9
Recurring basis
Corporate Borrowings:
Total liabilities at fair value	67.7
Recurring basis \| 6.00%/8.00% Cash/PIK Toggle Senior Secured Exchangeable Notes due 2030
Corporate Borrowings:
Bifurcated embedded derivative	5.5
Recurring basis \| New exchangeable notes
Corporate Borrowings:
Bifurcated embedded derivative	62.2
Recurring basis \| Significant unobservable inputs (Level 3)
Corporate Borrowings:
Total liabilities at fair value	67.7
Recurring basis \| Significant unobservable inputs (Level 3) \| 6.00%/8.00% Cash/PIK Toggle Senior Secured Exchangeable Notes due 2030
Corporate Borrowings:
Bifurcated embedded derivative	5.5
Recurring basis \| Significant unobservable inputs (Level 3) \| New exchangeable notes
Corporate Borrowings:
Bifurcated embedded derivative	$ 62.2

Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.