Significant Accounting Policies (Details 1) - USD ($)	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Accounting Policies [Abstract]
Shares, beginning of period	11,873,295	10,727,887	10,290,267
Shares issued	1,347,199	1,495,408	591,676
Shares redeemed	(402,549)	(350,000)	(154,056)
Shares, end of period	12,817,945	11,873,295	10,727,887
Amount, shares, beginning of period	$ 150,490,404	$ 135,573,317	$ 130,038,988
Amount, shares issued	19,581,163	19,053,855	7,449,999
Amount, shares redeemed	(5,019,764)	(4,136,768)	(1,915,670)
Amount, shares, end of period	$ 165,051,803	$ 150,490,404	$ 135,573,317