Fair Value Of Financial Instruments (Impact of EBITDA Multiple) (Details) - Cell C [Member] - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
EBITDA Multiple		6.75%
EBITDA Multiple Of 6.25 Times [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
EBITDA Multiple	6.25%
Sensitivity for fair value of investment	$ 149,179
EBITDA Multiple Of 6.75 Times [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
EBITDA Multiple	6.75%
Sensitivity for fair value of investment	$ 167,835
EBITDA Multiple Of 7.25 Times [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
EBITDA Multiple	7.25%
Sensitivity for fair value of investment	$ 186,490