Investment Management and Other Fees - Additional Information (Details)		1 Months Ended	12 Months Ended
	Nov. 01, 2014 USD ($)	Dec. 31, 2013 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2013 USD ($)	Nov. 30, 2013 fund
Investment [Line Items]
Base percentage adjustment, fund performance not within benchmark index			0.25%
Minimum performance to designated benchmark over prior rolling twelve months, percent			5.00%
Increase (decrease) in base advisory fees realized			$ (1,000,000)	$ (815,000)	$ (133,000)
Aggregate fees waived and expenses borne			$ 1,300,000	2,400,000	3,300,000
Fees waived and or expenses reimbursed U.S. Treasury Securities Cash Fund to maintain minimum yield				583,000	1,200,000
Minimum yield waivers recoverable, recapture period			3 years
Minimum yield waivers recoverable through 12/31/15			$ 510,000
Minimum yield waivers recoverable through 12/31/16			$ 498,000
Administrative services fee, per fund	$ 7,000	$ 10,000
Unitary management fee, percentage of average net assets			0.60%
Advisory fees			$ 6,682,000	7,760,000	12,189,000
Investor Class Shares [Member]
Investment [Line Items]
Previous administrative fee rate		0.08%
Administrative fee rate		0.10%
Institutional Class Shares [Member]
Investment [Line Items]
Previous administrative fee rate		0.06%
Administrative fee rate		0.08%
Offshore clients [Member]
Investment [Line Items]
Advisory fees			130,000	190,000	299,000
Performance fees			$ 0	$ 4,000	$ 19,000
Offshore fund [Member]
Investment [Line Items]
Number of funds liquidated | fund						1
Maximum [Member]
Investment [Line Items]
Shareholder services fee, percentage of share value in account			0.20%