Selected Quarterly Financial Data (Unaudited) - Quarterly Financial Information of Income Statement (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Operating revenues	$ 2,905	$ 2,742	$ 2,740	$ 3,052	$ 3,459	$ 4,473	$ 4,973	$ 4,413	$ 11,439	$ 17,318	$ 22,374
Income (loss) from continuing operations before income taxes	222	(12)	(1,424)	(23)	(608)	199	323	157	(1,237)	71	2,662
Tax expense (benefit)	(51)	14	(466)	(14)	(193)	84	145	64	(517)	100	1,024
Income (loss) from continuing operations	273	(26)	(958)	(9)	(415)	115	178	93	(720)	(29)	1,638
Loss on discontinued operations	(6)	(2)	(207)	(28)	(35)	(74)	(12)	(44)	(243)	(165)	(108)
Net income (loss)	267	(28)	(1,165)	(37)	(450)	41	166	49	(963)	(194)	1,530
Net income attributable to non-controlling interest	7	0	0	0	0	0	0	0	7	0	0
Net income (loss) attributable to U.S. Global Investors, Inc.	260	(28)	(1,165)	(37)	(450)	41	166	49	(970)	(194)	1,530
Comprehensive income (loss)	437	151	(1,052)	(236)	(598)	470	(31)	151	(700)	(8)	954
Comprehensive income (loss) attributable to U.S. Global Investors, Inc.	$ 421	$ 151	$ (1,052)	$ (236)	$ (598)	$ 470	$ (31)	$ 151	$ (716)	$ (8)	$ 954
Basic
Income (loss) from continuing operations (in dollars per share)	$ 0.02	$ 0.00	$ (0.06)	$ 0.00	$ (0.02)	$ 0.01	$ 0.01	$ 0.00	$ (0.04)	$ 0.00	$ 0.11
Loss from discontinued operations (in dollars per share)	$ 0.00	$ 0.00	$ (0.02)	$ 0.00	$ 0.00	$ (0.01)	$ 0.00	$ 0.00	$ (0.02)	$ (0.01)	$ (0.01)
Net income (loss) (in dollars per share)	$ 0.02	$ 0.00	$ (0.08)	$ 0.00	$ (0.02)	$ 0.00	$ 0.01	$ 0.00	$ (0.06)	$ (0.01)	$ 0.10
Diluted
Income (loss) from continuing operations (in dollars per share)	$ 0.02	$ 0.00	$ (0.06)	$ 0.00	$ (0.02)	$ 0.01	$ 0.01	$ 0.00	$ (0.04)	$ 0.00	$ 0.11
Loss from discontinued operations (in dollars per share)	$ 0.00	$ 0.00	$ (0.02)	$ 0.00	$ 0.00	$ (0.01)	$ 0.00	$ 0.00	$ (0.02)	$ (0.01)	$ (0.01)
Net income (loss) (in dollars per share)	$ 0.02	$ 0.00	$ (0.08)	$ 0.00	$ (0.02)	$ 0.00	$ 0.01	$ 0.00	$ (0.06)	$ (0.01)	$ 0.10