Fair Value Of Financial Instruments (Schedule Of Impact On Carrying Value Of Cell C Investment) (Details) $ in Thousands	Sep. 30, 2022 USD ($)
1.9% Increase [Member] | Weighted Average Cost Of Capital (WACC) Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Sensitivity for fair value of Cell C investment	$ 0
1.9% Increase [Member] | EBITDA Multiple [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Sensitivity for fair value of Cell C investment	1,246
3.2% Decrease [Member] | Weighted Average Cost Of Capital (WACC) Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Sensitivity for fair value of Cell C investment	226
3.2% Decrease [Member] | EBITDA Multiple [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Sensitivity for fair value of Cell C investment	$ 0