Fair Value Of Financial Instruments (Impact of EBITDA Multiple) (Details) - Cell C [Member] - USD ($) $ in Thousands	Mar. 31, 2019	Jun. 30, 2018
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
EBITDA Multiple	6.40%	6.75%
EBITDA Multiple Of 5.90 Times [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
EBITDA Multiple	5.90%
Sensitivity for fair value of investment	$ 105,601
EBITDA Multiple Of 6.40 Times [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
EBITDA Multiple	6.40%
Sensitivity for fair value of investment	$ 121,941
EBITDA Multiple Of 6.90 Times [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
EBITDA Multiple	6.90%
Sensitivity for fair value of investment	$ 138,347