Fair Value Of Financial Instruments (Fair Value Of Assets And Liabilities Measured On Recurring Basis) (Details) - Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Jun. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in Cell C	$ 167,835	$ 172,948
Cash, cash equivalents and restricted cash (included in other long-term assets)	598
Cash and cash equivalents (included in other long-term assets)		610
Fixed maturity investments (included in cash, cash equivalents and restricted cash)	7,853	8,304
Other	18	18
Total assets at fair value	176,304	181,880
DNI contingent consideration	26,839	27,222
Foreign exchange contracts	152
Total liabilities at fair value	26,991	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, cash equivalents and restricted cash (included in other long-term assets)	598
Cash and cash equivalents (included in other long-term assets)		610
Fixed maturity investments (included in cash, cash equivalents and restricted cash)	7,853	8,304
Total assets at fair value	8,451	8,914
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	18	18
Total assets at fair value	18	18
Foreign exchange contracts	152
Total liabilities at fair value	152
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment in Cell C	167,835	172,948
Total assets at fair value	167,835	172,948	$ 147,473	$ 151,003
DNI contingent consideration	26,839	27,222
Total liabilities at fair value	$ 26,839	$ 27,222