Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Thousands, shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Restricted cash	$ 37		$ 37		$ 37
Property, Plant and Equipment [Line Items]
Property and equipment, net	1,510		1,510		279
Depreciation expense	84	$ 3	95	$ 5
Prepaid clinical expenses	458		$ 458		$ 1,528
Potentially dilutive common shares related to the outstanding preferred stock, stock options, restricted stock units and warrants			8.9	7.9
Comprehensive loss	$ (10,650)	$ (4,284)	$ (19,605)	$ (9,412)
Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of the assets			2 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of the assets			7 years