Fair Value Of Financial Instruments (Schedule Of Key Valuation Inputs Used To Measure Fair Value Of Investment In Cell C) (Details) - Cell C [Member] R in Billions, $ in Billions	9 Months Ended	12 Months Ended
	Mar. 31, 2025 USD ($)	Jun. 30, 2024 USD ($)	Mar. 31, 2025 ZAR (R)	Jun. 30, 2024 ZAR (R)
Net adjusted external debt	$ 0.4	$ 0.4	R 7.8	R 7.9
Weighted Average Cost of Capital (WACC) Rate [Member] | Minimum [Member]
Investment fair value measurement inputs	21.00%
Weighted Average Cost of Capital (WACC) Rate [Member] | Maximum [Member]
Investment fair value measurement inputs	26.00%
Long Term Growth Rate [Member]
Investment fair value measurement inputs	4.50%	4.50%
Marketability Discount [Member]
Investment fair value measurement inputs	20.00%	20.00%
Minority Discount [Member]
Investment fair value measurement inputs	24.00%	24.00%