Contingencies - Additional Information (Detail) (USD $)	1 Months Ended		3 Months Ended	1 Months Ended
	Feb. 24, 2011	Jun. 16, 2011 Securities Litigation	Mar. 31, 2012 Securities Litigation Settlement of Litigation	Jun. 16, 2011 Securities Litigation Insurance Company	Jun. 16, 2011 Securities Litigation Income	Feb. 24, 2011 Securities Litigation Maximum	Feb. 24, 2011 Securities Litigation Mr. Therrien
Commitments and Contingencies Disclosure [Line Items]
Proceeds from sale of shares							$ 1,900,000
Number of shares sold							150,000
Percent of litigation settlement				50.00%	50.00%	30.00%
Litigation settlement, disgorgement payment							728,000
Litigation settlement, fines							100,000
Reimbursement to Mr. Therrien towards his disgorgement payment	500,000
Net amount to be recovered from insurance company	3,500,000
Proceeds from litigation settlement		1,300,000
Net insurance proceeds			$ 3,300,000