GOODWILL, INTANGIBLE ASSETS, NET, AND DIGITAL ASSETS HELD - Estimated future amortization (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended	12 Months Ended
	Sep. 30, 2025	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets
Impairment charge	$ 1.8
Impairment of intangible assets					$ 36.6	$ 81.0
Impairment, Intangible Asset, Statement of Income or Comprehensive Income [Extensible Enumeration]					Impairment of assets
Amortization expense					$ 70.2	88.7	$ 116.6
Amortization expense
Expected amortization, year one					62.7
Expected amortization, year two					55.9
Expected amortization, year three					50.3
Expected amortization, year four					45.7
Expected amortization, year five					40.5
Customer relationships
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets
Impairment, Intangible Asset, Finite-Lived, Statement of Income or Comprehensive Income [Extensible Enumeration]		Impairment of assets		Impairment of assets
Impairment of intangible assets		$ 17.1		$ 17.1
Digital
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets
Impairment of intangible assets			$ 81.0		0.0	81.0
Amortization expense					$ 0.0	$ 2.3