Significant Accounting Policies (Schedule Of Investment In Platinum) (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016 USD ($) oz	Mar. 31, 2015 USD ($) oz	Dec. 31, 2015 USD ($) oz
Significant Accounting Policies [Abstract]
Opening balance (in Ounces) | oz	463,267.0	514,614.2	514,614.2
Creations (in Ounces) | oz	43,368.8		58,059.6
Redemptions (in Ounces) | oz	(19,284.7)		(106,420.5)
Transfers of platinum to pay expenses (in Ounces) | oz	(687.1)		(2,986.3)
Closing balance (in Ounces) | oz	486,664.0		463,267.0
Opening balance	$ 403,969	$ 622,683	$ 622,683
Creations	41,460		62,044
Redemptions	(16,883)		(111,353)
Realized (loss) / gain on platinum distributed for the redemption of Shares	(8,563)	(3,442)	(31,912)
Transfers of platinum to pay expenses	(607)		(3,237)
Realized (loss) / gain on platinum transferred to pay expenses	(299)	(107)	(791)
Change in unrealized gain / (loss) on investment in platinum	55,907	$ (36,856)	(133,465)
Closing balance	$ 474,984		$ 403,969