Fair Value Of Financial Instruments (Fair Value Of Assets And Liabilities Measured On Recurring Basis) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in Cell C	$ 172,948
Cash and cash equivalents (included in other long-term assets)	610	$ 627
Fixed maturity investment (included in cash and cash equivalents)	8,304	5,160
Other	18	37
Total assets at fair value	181,880	5,824
DNI contingent consideration (Note 3)	27,222
Total liabilities at fair value	27,222
Quoted Price In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents (included in other long-term assets)	610	627
Fixed maturity investment (included in cash and cash equivalents)	8,304	5,160
Total assets at fair value	8,914	5,787
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	18	37
Total assets at fair value	18	$ 37
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in Cell C	172,948
Total assets at fair value	172,948
DNI contingent consideration (Note 3)	27,222
Total liabilities at fair value	$ 27,222