Business (Details) $ in Thousands		1 Months Ended	6 Months Ended		42 Months Ended
	Jan. 14, 2014	Jul. 31, 2014 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net cash used for operating activities			$ 11,242	$ 4,685	$ 31,000
Schedule of Capitalization, Equity [Line Items]
Cash and cash equivalents			$ 36,045		$ 36,045	$ 48,555	$ 3,888	$ 8,629
Reverse stock split ratio	0.02
Underwriting Agreement [Member]
Schedule of Capitalization, Equity [Line Items]
Proceeds from the underwriting agreement, including additional shares sold, net of cost		$ 53,100