Statements of Changes in Net Assets (Unaudited) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Net Assets, Beginning of Period	$ 501,546,756	$ 775,343,105	$ 1,232,799,956	$ 1,209,866,609	$ 775,343,105	$ 1,209,866,609
Operations:
Net investment income (loss)	(419,416)	1,028,255	4,188,045	4,491,037	608,839	8,679,082
Net realized gain (loss)	(82,704,409)	(224,167,336)	(12,333,646)	1,925,332	(306,871,745)	(10,408,314)
Net change in unrealized appreciation/depreciation	140,833,410	(144,962,309)	(7,462,082)	163,896,481	(4,128,899)	156,434,399
Net increase (decrease) in net assets resulting from operations	57,709,585	(368,101,390)	(15,607,683)	170,312,850	(310,391,805)	154,705,167
Capital Share Transactions:
Contributions for Shares issued	69,679,590	134,854,545	891,320	24,217,916
Distributions for Shares redeemed	(19,691,724)	(40,549,504)	(341,748,867)	(171,597,419)
Net increase (decrease) in net assets from capital share transactions	49,987,866	94,305,041	(340,857,547)	(147,379,503)
Increase (decrease) in net assets	107,697,451	(273,796,349)	(356,465,230)	22,933,347
Net Assets, End of Period	$ 609,244,207	$ 501,546,756	$ 876,334,726	$ 1,232,799,956	$ 609,244,207	$ 876,334,726
Shares issued and redeemed
Shares issued (in shares)					17,100,000	1,750,000
Shares redeemed (in shares)					(5,850,000)	(32,500,000)
Net increase (decrease) in Shares issued and outstanding (in shares)					11,250,000	(30,750,000)