Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Direct Offering [Member] Common Stock [Member]	Direct Offering [Member] Additional Paid-in Capital [Member]	Direct Offering [Member] Share Issuance Obligation [Member]	Direct Offering [Member] Retained Earnings [Member]	Direct Offering [Member] AOCI Attributable to Parent [Member]	Direct Offering [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Share Issuance Obligation [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Jul. 31, 2019							180,896,431
Balance at Jul. 31, 2019							$ 181	$ 336,048	$ 187	$ (262,202)	$ 13	$ 74,227
Issued as anniversary fees for credit facility (in shares)							1,743,462
Issued as anniversary fees for credit facility							$ 2	1,398	0	0	0	1,400
Issued upon vesting of RSUs and PRSUs (in shares)							105,844
Issued upon vesting of RSUs and PRSUs							$ 0	(154)	104	0	0	$ (50)
Issued upon exercise of stock options (in shares)												0
Common stock issued for consulting services (in shares)							380,933
Common stock issued for consulting services							$ 0	351	0			$ 351
Common stock issued under Stock Incentive Plan (in shares)							1,509,200
Common stock issued under Stock Incentive Plan							$ 2	1,308	(187)			1,123
Amortization of stock-based compensation								2,085				2,085
Net income (loss) for the year							0	0	0	(14,610)	0	(14,610)
Other comprehensive income (loss)							0	0	0	0	(133)	(133)
Issued for consulting services							$ 0	23	0	0	0	23
Balance (in shares) at Jul. 31, 2020							184,635,870
Balance at Jul. 31, 2020							$ 185	341,059	104	(276,812)	(120)	64,416
Issued as anniversary fees for credit facility (in shares)							1,249,039
Issued as anniversary fees for credit facility							$ 1	1,169	0	0	0	1,170
Issued under ATM offering, net of issuance costs (in shares)	26,136,364						15,934,606
Issued under ATM offering, net of issuance costs	$ 26	$ 52,515	$ 0	$ 0	$ 0	$ 52,541	$ 16	35,219				35,235
Issued upon vesting of RSUs and PRSUs (in shares)							536,361
Issued upon vesting of RSUs and PRSUs							$ 1	(1,255)	256	0	0	$ (998)
Issued upon exercise of stock options (in shares)							3,326,255					3,326,255
Issued upon exercise of stock options							$ 3	1,913				$ 1,916
Issued upon exercise of warrants (in shares)							3,692,865
Issued upon exercise of warrants							$ 4	3,585				3,589
Common stock issued for consulting services (in shares)							312,302
Common stock issued for consulting services							$ 0	953	0	0	0	953
Common stock issued under Stock Incentive Plan (in shares)							973,204
Common stock issued under Stock Incentive Plan							$ 1	1,593	0	0	0	1,594
Amortization of stock-based compensation							0	3,260	0	0	0	3,260
Net income (loss) for the year							0	0	0	(14,813)	0	(14,813)
Other comprehensive income (loss)											613	613
Issued in connection with ATM offering							0	1,518	0	0	0	1,518
Issued in connection with a direct offering as issuance costs							$ 0	461	0	0	0	461
Balance (in shares) at Jul. 31, 2021							236,796,866
Balance at Jul. 31, 2021							$ 237	441,990	360	(291,625)	493	151,455
Issued as anniversary fees for credit facility (in shares)							161,594
Issued as anniversary fees for credit facility							$ 0	600	0	0	0	600
Issued under ATM offering, net of issuance costs (in shares)							47,507,536
Issued under ATM offering, net of issuance costs							$ 48	163,707				163,755
Issued upon vesting of RSUs and PRSUs (in shares)							628,803
Issued upon vesting of RSUs and PRSUs							$ 0	(2,188)	(360)	0	0	$ (2,548)
Issued upon exercise of stock options (in shares)							2,152,095					2,152,095
Issued upon exercise of stock options							$ 2	932				$ 934
Issued upon exercise of warrants (in shares)							1,771,869
Issued upon exercise of warrants							$ 2	3,323				3,325
Issued for acquisition of mineral properties (in shares)							111,864
Issued for acquisition of mineral properties							$ 0	426				426
Common stock issued for consulting services (in shares)							56,273
Common stock issued for consulting services							$ 0	187				187
Common stock issued under Stock Incentive Plan (in shares)							451,407
Common stock issued under Stock Incentive Plan							$ 0	1,478				1,478
Amortization of stock-based compensation								2,724				2,724
Net income (loss) for the year							0	0	0	5,252	0	5,252
Other comprehensive income (loss)							$ 0	0	0	0	(679)	(679)
Balance (in shares) at Jul. 31, 2022							289,638,307
Balance at Jul. 31, 2022							$ 289	$ 613,179	$ 0	$ (286,373)	$ (186)	$ 326,909