Income Taxes (Provisions For Income Taxes By Location Of Taxing Jurisdiction) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019		Jun. 30, 2018
Income Tax [Line Items]
Current income tax	$ 1,652	$ 4,789		$ 90,467
Deferred taxation (benefit) charge	932	(8,917)		10,108
Foreign tax credits generated-United States	72	(944)		(55,778)
Changes in enacted tax rate	0	0		309
Income tax provision	2,656	(5,072)	[1]	45,106	[1]
South Africa [Member]
Income Tax [Line Items]
Current income tax	1,552	3,689		35,745
Deferred taxation (benefit) charge	653	(8,538)		9,149
United States [Member]
Income Tax [Line Items]
Current income tax	12	1,100		55,788
Deferred taxation (benefit) charge	0	4		477
Other Income Tax Segment [Member]
Income Tax [Line Items]
Current income tax	88	0		(1,066)
Deferred taxation (benefit) charge	$ 279	$ (383)		$ 482

[1] Refer to Note 1