Accrued Expenses (Detail) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Schedule of Accrued Liabilities [Line Items]
Payroll and benefits	$ 2,162,634	$ 2,477,833
Professional fees	469,991	642,853
Clinical trial costs	67,767	102,414
Restructuring costs	283,063	933,732
Other	1,520,096	1,680,212
Total	$ 4,503,551	$ 5,837,044

Carrying value as of the balance sheet date of obligations incurred through that date and payable for professional fees, such as for legal and accounting services received. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Carrying value as of the balance sheet date of the obligations incurred through that date and payable for employees' services provided. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable arising from transactions not otherwise specified in the taxonomy. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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