Schedules of Investments (Unaudited) - Investments (Details) $ in Thousands	Mar. 31, 2016 USD ($) oz	Dec. 31, 2015 USD ($) oz	Mar. 31, 2015 USD ($) oz	Dec. 31, 2014 USD ($) oz
Gold bullion | oz	5,990,500	4,905,600	5,302,300	5,182,200
Gold bullion	$ 7,174,407	$ 5,910,176	$ 6,411,164	$ 6,254,868
Gold bullion	7,410,267	5,210,940
Less Liabilities	(1,624)	(1,137)
Net Assets	$ 7,408,643	$ 5,209,803		$ 6,213,387