Accrued Expenses and Other Current Liabilities - Components of Accrued Expenses and Other Current Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Payables And Accruals [Abstract]
Clinical and preclinical trials	$ 29,043	$ 25,150
Payroll and payroll-related	12,682	13,439
Royalties payable	4,809	2,296
Interest payable	1,698	1,698
Accrued professional services and other current liabilities	9,253	6,368
Total	$ 57,485	$ 48,951

Carrying value as of the balance sheet date of obligations incurred through that date and payable for royalties. 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 [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. 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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