Related Party Transactions - Additional Information (Details) (USD $)	12 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2012
Related Party Transaction [Line Items]
Advisory fees	$ 7,760,000		$ 12,189,000		$ 14,933,000
Trading, fair value	17,817,000	[1]	4,758,000	[1]
Available-for-sale securities, fair value	6,196,000	[2],[3]	9,053,000	[2],[3]
USGIF and offshore clients [Member]
Related Party Transaction [Line Items]
Fair Value investment included in Cash and Cash Equivalents and trading securities	19,400,000		29,700,000
Dividend income	132,000		114,000		117,000
Unrealized gain (losses) on related party securities	(143,000)		(147,000)		50,000
Chief Executive Officer, Trustee of USGIF [Member]
Related Party Transaction [Line Items]
Investment advisory fees receivable	1,300,000		964,000
Charlemagne Capital Limited [Member]
Related Party Transaction [Line Items]
Available-for-sale securities, fair value	1,300,000
Offshore fund [Member]
Related Party Transaction [Line Items]
Number of funds to which Company provides advisory services	2
Trading, fair value	998,000	[1]	786,000	[1]
Available-for-sale securities, fair value			4,712,000	[3]
Offshore fund [Member] | Chief Executive Officer, Director of Meridian Offshore Funds [Member]
Related Party Transaction [Line Items]
Advisory fees	194,000		318,000		358,000
Offshore fund [Member] | Energy and natural resource sectors [Member] | Significant Other Inputs (Level 2) [Member]
Related Party Transaction [Line Items]
Trading, fair value			$ 786,000

[1] Unrealized and realized gains and losses on trading securities are included in earnings in the statement of operations.

[2] Net unrealized gains on available-for-sale securities gross and net of tax as of June 30, 2014, are $1,345 and $888, respectively, and as of June 30, 2013, are $988 and $652, respectively.

[3] Unrealized gains and losses on available-for-sale securities are excluded from earnings and recorded in other comprehensive income (loss) as a separate component of shareholders’ equity until realized.