Note 11 - Income Taxes - Tax Credit Carryforwards (Details)	May 31, 2019 CAD ($)
CANADA
Tax Credit Carry-forward, Amount	$ 13,583,000
UNITED STATES
Tax Credit Carry-forward, Amount	17,930,000
Tax Year 2029 [Member] | CANADA
Tax Credit Carry-forward, Amount
Tax Year 2029 [Member] | UNITED STATES
Tax Credit Carry-forward, Amount	1,293,000
Tax Year 2030 [Member] | CANADA
Tax Credit Carry-forward, Amount
Tax Year 2030 [Member] | UNITED STATES
Tax Credit Carry-forward, Amount	2,000
Tax Year 2031 [Member] | CANADA
Tax Credit Carry-forward, Amount	379,000
Tax Year 2031 [Member] | UNITED STATES
Tax Credit Carry-forward, Amount	192,000
Tax Year 2032 [Member] | CANADA
Tax Credit Carry-forward, Amount	1,089,000
Tax Year 2032 [Member] | UNITED STATES
Tax Credit Carry-forward, Amount	1,646,000
Tax Year 2033 [Member] | CANADA
Tax Credit Carry-forward, Amount	1,443,000
Tax Year 2033 [Member] | UNITED STATES
Tax Credit Carry-forward, Amount	2,173,000
Tax Year 2034 [Member] | CANADA
Tax Credit Carry-forward, Amount	1,733,000
Tax Year 2034 [Member] | UNITED STATES
Tax Credit Carry-forward, Amount	4,233,000
Tax Year 2035 [Member] | CANADA
Tax Credit Carry-forward, Amount	1,806,000
Tax Year 2035 [Member] | UNITED STATES
Tax Credit Carry-forward, Amount	1,967,000
Tax Year 2036 [Member] | CANADA
Tax Credit Carry-forward, Amount	1,354,000
Tax Year 2036 [Member] | UNITED STATES
Tax Credit Carry-forward, Amount	1,940,000
Tax Year 2037 [Member] | CANADA
Tax Credit Carry-forward, Amount	1,624,000
Tax Year 2037 [Member] | UNITED STATES
Tax Credit Carry-forward, Amount	1,342,000
Tax Year 2038 [Member] | CANADA
Tax Credit Carry-forward, Amount	1,949,000
Tax Year 2038 [Member] | UNITED STATES
Tax Credit Carry-forward, Amount	1,538,000
Tax Year 2039 [Member] | CANADA
Tax Credit Carry-forward, Amount	2,206,000
Tax Year 2039 [Member] | UNITED STATES
Tax Credit Carry-forward, Amount	$ 1,604,000