Investment Management Transfer Agent and Other Fees - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		1 Months Ended						6 Months Ended
	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Offshore funds	Dec. 31, 2012 Offshore funds	Dec. 31, 2013 Offshore funds	Dec. 31, 2012 Offshore funds	Dec. 31, 2013 Investor Class Shares Minimum	Dec. 31, 2013 Investor Class Shares Maximum	Dec. 31, 2013 Institutional Class Shares Minimum	Dec. 31, 2013 Institutional Class Shares Maximum	Dec. 31, 2013 Offshore Funds Investment Advisory Services company	Nov. 30, 2013 Offshore Funds Investment Advisory Services fund	Dec. 31, 2013 Government Fund	Dec. 31, 2013 U.S. Treasury Securities Cash Fund
Investment Management And Other Fees [Line Items]
Base advisory fee adjustment, description	Is adjusted upwards or downwards by 0.25 percent when there is a performance difference of 5 percent or more between a fund’s performance and that of its designated benchmark index over the prior rolling 12 months.
Base percentage adjustment when fund performance is not within limits to benchmark index	0.25%	0.25%		0.25%
Percent minimum performance to designated benchmark over prior rolling 12 months	5.00%	5.00%		5.00%
Increase (decrease) in base advisory fees realized		$ (286,070)	$ 181,850	$ (418,681)	$ (165,064)
Date through which the company agreed to contractually limit the expenses of the two fixed income funds and the institutional class of Global Resources Fund		4/30/2014
Aggregate fees waived and expenses borne		892,841	854,558	1,748,211	1,704,599
Fees waived and or expenses reimbursed U.S. Treasury Securities Cash Fund to maintain minimum yield		248,813	286,600	583,577	587,235
Minimum yield waivers recoverable through 12/31/14																(736,531)
Minimum yield waivers recoverable through 12/31/15																(509,874)
Minimum yield waivers recoverable through 12/31/16																(498,342)
Minimum yield waivers subject to future recovery																	0
Annual administrative fee rate										0.08%	0.10%	0.06%	0.08%
Administrative services fees on average daily net assets	10,000
Number of offshore clients company provides advisory services for														3
Number of funds liquidated															1
Recorded advisory and performance fees						$ 52,790	$ 79,012	$ 105,068	$ 169,574