Fair Value Of Financial Instruments (Schedule Of Impact On Carrying Value Of Cell C Investment) (Details) $ in Thousands	Jun. 30, 2022 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Percentage increase not impacting investment value	1.00%
Percentage decrease not impacting investment value	1.00%
Percentage increase impacting investment value	1.90%
Percentage decrease impacting investment value	3.20%
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	28
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	431
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