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BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES - Gain on Sale of Subsidiary (Details) R in Millions, $ in Millions			3 Months Ended		9 Months Ended
	Mar. 06, 2025 USD ($)	Mar. 06, 2025 ZAR (R)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 ZAR (R)	Mar. 06, 2025 ZAR (R)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Taxes			$ 37.4	$ 122.4	$ 287.6	$ 291.1
Disposal Group, Disposed of by Sale, Not Discontinued Operations | South Africa Fiber
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds received at closing	$ 137.7							R 2,500.0
Net assets at closing	(84.1)
Total gain on sale included in Other operating expenses	53.6				53.6
Taxes	$ 20.8	R 377.9
Taxes payable			$ 7.6		$ 7.6		R 131.5

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