ROYALTY AGREEMENT, UNALLOCATED RESERVE AND DISTRIBUTIONS (Details) - USD ($)		3 Months Ended		9 Months Ended
	Oct. 08, 2021	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2021	Oct. 31, 2020	Jan. 31, 2021
Unallocated Cash and Securities portion of Unallocated Reserve
Cash and U.S. Government securities		$ 45,859,961		$ 45,859,961		$ 22,407,610
Distribution payable		(18,630,414)		(18,630,414)		(6,035,205)
Unallocated cash and U.S. Government securities		27,229,547		27,229,547		$ 16,372,405
Reconciliation of Trust's Unallocated Reserve
Beginning Balance		38,949,339	$ 12,115,434	16,477,049	$ 11,831,017
Net income		15,992,906	5,126,399	51,322,806	13,414,023
Distributions declared		(18,630,414)	(4,723,204)	(31,488,024)	(12,726,411)
Ending Balance		$ 36,311,831	$ 12,518,629	$ 36,311,831	$ 12,518,629
Distributions declared per unit (in dollars per unit)	$ 1.42	$ 1.4200	$ 0.3600	$ 2.4000	$ 0.9700
Distribution declared per unit		$ 1.4200	$ 0.3600
Unallocated Reserve member
Reconciliation of Trust's Unallocated Reserve
Beginning Balance		$ 38,949,336	$ 12,115,431	$ 16,477,046	$ 11,831,014
Net income		15,992,906	5,126,399	51,322,806	13,414,023
Distributions declared		(18,630,414)	(4,723,204)	(31,488,024)	(12,726,411)
Ending Balance		36,311,828	12,518,626	36,311,828	12,518,626
Trust Corpus
Reconciliation of Trust's Unallocated Reserve
Beginning Balance		3	3	3	3
Ending Balance		$ 3	$ 3	$ 3	$ 3