Investment Management Transfer Agent And Other Fees [Abstract]

Base advisory fee adjustment, description

Is adjusted upwards or downwards by 0.25 percent if 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

Aggregate fees waived and expenses borne

3,328,326

3,132,831

3,131,906

Fees waived and or expenses reimbursed U.S. Treasury Securities Cash Fund to maintain minimum yield

719,660

Minimum yield waivers recoverable through 12/31/13

1,562,956

Minimum yield waivers recoverable through 12/31/15

1,245,458

Investment Management Transfer Agent and Other Fees - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Jun. 30, 2013 Funds	Jun. 30, 2013 Funds	Jun. 30, 2012	Jun. 30, 2011
Investment Management Transfer Agent And Other Fees [Abstract]
Number of equity funds with base advisory fee adjustment	9
Base advisory fee adjustment, description	Is adjusted upwards or downwards by 0.25 percent if 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
Increase (decrease) in base advisory fees realized		$ 133,011	$ 2,230,811	$ 2,380,608
Aggregate fees waived and expenses borne		3,328,326	3,132,831	3,131,906
Number of funds, company agreed to cap the expenses		13
Fees waived and or expenses reimbursed U.S. Treasury Securities Cash Fund to maintain minimum yield		719,660
Fees waived and or expenses reimbursed for U.S. Government Securities Savings Fund to maintain minimum yield		484,206
Minimum yield waivers recoverable through 12/31/13		1,562,956
Minimum yield waivers recoverable through 12/31/14		1,604,076
Minimum yield waivers recoverable through 12/31/15		1,245,458
Minimum yield waivers recoverable through 12/31/16		$ 616,631