| **Accounts Payable and Accrued Expenses (Details) (USD $)In Thousands, unless otherwise specified** | Jun. 30, 2014 | Dec. 31, 2013 |
|-----------------------------------------------------------------------------------------------------|---------------|---------------|
| **Accounts Payable and Accrued Expenses [Abstract]**                                                |          |          |
| Accrued consulting and clinical trial costs                                                         | $ 1,939       | $ 2,672       |
| Accrued payroll and related costs                                                                   | 1,329         | 2,123         |
| Restructuring accrual                                                                               | 49            | 0             |
| Legal and professional fees                                                                         | 545           | 608           |
| Accounts payable                                                                                    | 186           | 793           |
| Other                                                                                               | 189           | 316           |
| Total                                                                                               | $ 4,237       | $ 6,512       |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
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| - Definition
Current portion of the carrying value as of the balance sheet date of obligations incurred through that date and payable for consulting services and clinical trials. (Clinical trials are used to determine whether new biomedical or behavioral interventions are safe, efficacious, and effective.)
+ References
No definition available.
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| - Definition
Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.
+ References
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| - Definition
Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).
+ References
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| - Definition
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).
+ References
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| - Definition
Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).
+ References
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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).
+ References
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| - Definition
Carrying amount as of the balance sheet date of known and estimated obligations associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, which are expected to be paid in the next twelve months or in the normal operating cycle if longer. Costs of such activities include those for one-time termination benefits, termination of an operating lease or other contract, consolidating or closing facilities, relocating employees, and costs associated with an ongoing benefit arrangement, but excludes costs associated with the retirement of a long-lived asset.
+ References
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