Statements of Assets and Liabilities (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Statements of Assets and Liabilities [Abstract]
Common stock, shares authorized	unlimited	unlimited
Common stock, par value	$ 0	$ 0
Investment in platinum at cost	$ 629,783	$ 614,675
Net asset value per share	$ 94.01	$ 84.12
Common stock, shares issued	5,050,000	4,750,000
Common stock, shares outstanding	5,050,000	4,750,000