Accounts Payable and Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Accounts Payable and Accrued Expenses [Abstract]
Accrued consulting and clinical trial costs	$ 2,565	$ 2,193
Accrued payroll and related costs	2,110	1,552
Restructuring accrual	89	813
Legal and professional fees	833	774
Accounts payable	234	229
Other	73	79
Total	$ 5,904	$ 5,640