Short-Term Credit Facilities (Summary Of Short-Term Credit Facilities) (Details) $ in Thousands, R in Millions		Mar. 31, 2018 ZAR (R)	Mar. 31, 2018 USD ($)	Jan. 29, 2018 USD ($)	Jun. 30, 2017 USD ($)
Short-term facility utilized			$ 3,400		$ 16,579	[1]
Overdraft Facility [Member]
Short-term facility available		R 50	4,200
South Africa [Member] | Overdraft Facility [Member]
Short-term facility available	[2]		21,100		19,109
South Africa [Member] | Indirect And Derivative Facilities [Member]
Short-term facility available			12,700		11,491
Short-term facility utilized			9,136		10,000
Bank Frick [Member] | United States [Member]
Short-term facility available	[2]		10,000
Short-term facility utilized	[2]		3,400
Bank Frick [Member] | United States [Member] | Overdraft Facility [Member]
Short-term facility available				$ 10,000
Bank Frick [Member] | Europe [Member]
Short-term facility available	[2]				66,579
Short-term facility utilized	[2]				16,579
Nedbank Limited [Member] | South Africa [Member]
Short-term facility available			33,800		30,600
Short-term facility utilized			$ 9,136		$ 10,000

[1] Derived from audited financial statements

[2] Utilized amount included in short-term facilities on the unaudited condensed consolidated balance sheets.