Operating Segments (Long-Lived Assets Based On Geographical Location) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 792,449	$ 344,566	$ 339,777
South Africa [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	498,418	74,370	69,213
South Korea [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	177,388	192,473	221,459
Rest Of World [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 116,643	$ 77,723	$ 49,105