Document And Entity Information - shares	9 Months Ended
	Mar. 31, 2018	Apr. 27, 2018
Document Information [Line Items]
Entity Registrant Name	U S GLOBAL INVESTORS INC
Document Type	10-Q
Current Fiscal Year End Date	--06-30
Amendment Flag	false
Entity Central Index Key	0000754811
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Well-known Seasoned Issuer	No
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q3
Common Class A [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		13,075,705
Common Class C [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		2,068,857
Common Class B [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		0