Short-Term Facilities (Summary Of Short-Term Credit Facilities) (Details) $ in Thousands, R in Millions		Jun. 30, 2018 ZAR (R)	Jun. 30, 2018 USD ($)	Jan. 29, 2018 USD ($)	Jun. 30, 2017 USD ($)
Short-term facility utilized					$ 16,579	[1]
South Africa [Member] | Overdraft Facility [Member]
Short-term facility available	[2]		18,200		19,109
South Africa [Member] | Indirect And Derivative Facilities [Member]
Short-term facility available			11,000		11,491
Short-term facility utilized			7,871		10,000
Bank Frick [Member] | United States [Member]
Short-term facility available	[2]		10,000
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			29,200		30,600
Short-term facility utilized			7,871		10,000
Nedbank Limited [Member] | South Africa [Member] | Overdraft Facility [Member]
Short-term facility available		R 50	3,600
Short-term facility utilized			0		$ 0
Nedbank Limited [Member] | South Africa [Member] | Indirect And Derivative Facilities [Member]
Short-term facility available		R 150	$ 11,000

[1] Refer to Note 1.

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