Fair Value Of Financial Instruments (Fair Value Of Assets And Liabilities Measured On Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Jun. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in Cell C	$ 206,970
Cash and cash equivalents (included in other long-term assets)	701	$ 627
Fixed maturity investment (included in cash and cash equivalents)	9,230	5,160
Other	40	37
Total assets at fair value	216,941	5,824
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)	701	627
Fixed maturity investment (included in cash and cash equivalents)	9,230	5,160
Total assets at fair value	9,931	5,787
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	40	37
Total assets at fair value	40	$ 37
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in Cell C	206,970
Total assets at fair value	$ 206,970