CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Share Issuance Obligation [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Balance at Jul. 31, 2014	$ 39,423,599	$ 90,972	$ 208,008,312	$ 0	$ (168,662,146)	$ (13,539)
Balance (in shares) at Jul. 31, 2014		90,966,558
Common stock Issued for equity financing, net of issuance costs	7,659,139	$ 5,280	7,653,859	0	0	0
Common stock Issued for equity financing, net of issuance costs (in shares)		5,280,045
Common stock Issued upon exercise of stock options	24,550	$ 305	24,245	0	0	0
Common stock Issued upon exercise of stock options (in shares)		304,657
Stock-based compensation Common stock issued for consulting services	1,851,074	$ 1,111	1,849,963	0	0	0
Stock-based compensation Common stock issued for consulting services (in shares)		1,108,390
Stock-based compensation Common stock issued for bonuses/under Stock Incentive Plan	235,490	$ 173	235,317	0	0	0
Stock-based compensation Common stock issued for bonuses/under Stock Incentive Plan (in shares)		174,437
Stock-based compensation Stock options issued to consultants	588,207	$ 0	588,207	0	0	0
Stock-based compensation Stock options issued to management	1,617,937	0	1,617,937	0	0	0
Stock-based compensation Stock options issued to employees	1,325,040	0	1,325,040	0	0	0
Warrants Issued for equity financing	1,418,116	0	1,418,116	0	0	0
Warrants Issued for equity financing as issuance costs	206,533	0	206,533	0	0	0
Net loss for the year	(23,361,928)	0	0	0	(23,361,928)	0
Other comprehensive income (loss)	(1,092)	0	0	0	0	(1,092)
Balance at Jul. 31, 2015	30,986,665	$ 97,841	222,927,529	0	(192,024,074)	(14,631)
Balance (in shares) at Jul. 31, 2015		97,834,087
Common stock Issued for equity financing, net of issuance costs	8,365,037	$ 12,365	8,352,672	0	0	0
Common stock Issued for equity financing, net of issuance costs (in shares)		12,364,704
Common stock Issued upon exercise of stock options	225,115	$ 682	224,433	0	0	0
Common stock Issued upon exercise of stock options (in shares)		682,167
Common stock Issued for credit facility	1,700,000	$ 1,712	1,698,288	0	0	0
Common stock Issued for credit facility (in shares)		1,711,933
Common stock Issued for property acquisition	1,226,875	$ 1,334	1,225,541	0	0	0
Common stock Issued for property acquisition (in shares)		1,333,560
Common stock Issued for settlement of liabilities	453,444	$ 487	452,957	0	0	0
Common stock Issued for settlement of liabilities (in shares)		487,574
Stock-based compensation Common stock issued for consulting services	1,372,381	$ 1,429	1,370,952	0	0	0
Stock-based compensation Common stock issued for consulting services (in shares)		1,429,650
Stock-based compensation Common stock issued for bonuses/under Stock Incentive Plan	726,244	$ 820	725,424	0	0	0
Stock-based compensation Common stock issued for bonuses/under Stock Incentive Plan (in shares)		826,782
Stock-based compensation Stock options issued to consultants	78,014	$ 0	78,014	0	0	0
Stock-based compensation Stock options issued to management	735,991	0	735,991	0	0	0
Stock-based compensation Stock options issued to employees	171,533	0	171,533	0	0	0
Warrants Issued for equity financing	1,619,480	0	1,619,480	0	0	0
Warrants extension for credit facility	104,915	0	104,915	0	0	0
Warrants extension for mineral property	14,155	0	14,155	0	0	0
Net loss for the year	(17,329,872)	0	0	0	(17,329,872)	0
Other comprehensive income (loss)	(99)	0	0	0	0	(99)
Balance at Jul. 31, 2016	30,449,878	$ 116,670	239,701,884	0	(209,353,946)	(14,730)
Balance (in shares) at Jul. 31, 2016		116,670,457
Common stock Issued for equity financing, net of issuance costs	19,421,351	$ 17,331	19,404,020	0	0	0
Common stock Issued for equity financing, net of issuance costs (in shares)		17,330,836
Common stock Issued upon exercise of stock options	56,925	$ 266	56,659	0	0	0
Common stock Issued upon exercise of stock options (in shares)		264,727
Common stock Issued upon exercise of warrants	2,387,660	$ 1,989	2,385,671	0	0	0
Common stock Issued upon exercise of warrants (in shares)		1,989,717
Common stock Issued for credit facility	1,100,000	$ 739	1,099,261	0	0	0
Common stock Issued for credit facility (in shares)		738,503
Common stock Issued for property acquisition	87,617	$ 62	87,555	0	0	0
Common stock Issued for property acquisition (in shares)		61,939
Common stock Issued for mineral property	48,672	$ 46	48,626	0	0	0
Common stock Issued for mineral property (in shares)		46,800
Common stock Issued for settlement of liabilities	1,524,650	$ 1,016	1,523,634	0	0	0
Common stock Issued for settlement of liabilities (in shares)		1,015,940
Stock-based compensation Common stock issued for consulting services	1,107,937	$ 862	1,107,075	0	0	0
Stock-based compensation Common stock issued for consulting services (in shares)		865,386
Stock-based compensation Common stock issued for bonuses/under Stock Incentive Plan	1,584,394	$ 834	945,418	638,142	0	0
Stock-based compensation Common stock issued for bonuses/under Stock Incentive Plan (in shares)		830,819
Stock-based compensation Stock options issued to consultants	469,815	$ 0	469,815	0	0	0
Stock-based compensation Stock options issued to management	473,811	0	473,811	0	0	0
Stock-based compensation Stock options issued to employees	369,663	0	369,663	0	0	0
Warrants Issued for equity financing	4,409,570	0	4,409,570	0	0	0
Warrants Issued for equity financing as issuance costs	614,490	0	614,490	0	0	0
Net loss for the year	(17,971,056)	0	0	0	(17,971,056)	0
Other comprehensive income (loss)	28	0	0	0	0	28
Balance at Jul. 31, 2017	$ 46,135,405	$ 139,815	$ 272,697,152	$ 638,142	$ (227,325,002)	$ (14,702)
Balance (in shares) at Jul. 31, 2017		139,815,124