Accounts Payable and Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Accounts payable and accrued expenses [Abstract]
Accrued consulting and clinical trial costs	$ 2,672	$ 2,193
Accrued payroll and related costs	2,123	1,552
Restructuring accrual	0	813
Legal and professional fees	608	774
Accounts payable	793	229
Other	316	79
Total	$ 6,512	$ 5,640