Earnings Per Share - Computation for Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share [Abstract]
Loss from continuing operations	$ (2,052)	$ (994)	$ (841)	$ (89)	$ 273	$ (26)	$ (958)	$ (9)	$ (3,976)	$ (720)	$ (29)
Less: Income attributable to non-controlling interest in subsidiary	1	13	1	39	7	0	0	0	54	7	0
Loss from continuing operations attributable to U.S. Global Investors, Inc.									(4,030)	(727)	(29)
Loss from discontinued operations attributable to U.S. Global Investors, Inc.					(6)	(2)	(207)	(28)	0	(243)	(165)
Net income (loss) attributable to U.S. Global Investors, Inc.	$ (2,053)	$ (1,007)	$ (842)	$ (128)	$ 260	$ (28)	$ (1,165)	$ (37)	$ (4,030)	$ (970)	$ (194)
Weighted average number of outstanding shares
Basic (shares)									15,399,831	15,459,022	15,482,612
Employee stock options (shares)									0	0	0
Diluted (shares)									15,399,831	15,459,022	15,482,612
Basic
Loss from continuing operations (in dollars per share)	$ (0.13)	$ (0.07)	$ (0.05)	$ (0.01)	$ 0.02	$ 0.00	$ (0.06)	$ 0.00	$ (0.26)	$ (0.04)	$ 0.00
Loss from discontinued operations (in dollars per share)	0.00	0.00	0.00	0.00	0.00	0.00	(0.02)	0.00	0.00	(0.02)	(0.01)
Net income (loss) attributable to U.S. Global Investors, Inc. (in dollars per share)	(0.13)	(0.07)	(0.05)	(0.01)	0.02	0.00	(0.08)	0.00	(0.26)	(0.06)	(0.01)
Diluted
Loss from continuing operations (in dollars per share)	(0.13)	(0.07)	(0.05)	(0.01)	0.02	0.00	(0.06)	0.00	(0.26)	(0.04)	0.00
Loss from discontinued operations (in dollars per share)	0.00	0.00	0.00	0.00	0.00	0.00	(0.02)	0.00	0.00	(0.02)	(0.01)
Net income (loss) attributable to U.S. Global Investors, Inc. (in dollars per share)	$ (0.13)	$ (0.07)	$ (0.05)	$ (0.01)	$ 0.02	$ 0.00	$ (0.08)	$ 0.00	$ (0.26)	$ (0.06)	$ (0.01)