Business (Details) - USD ($) $ in Thousands	6 Months Ended		54 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Dec. 31, 2015	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net cash used for operating activities since January 2012	$ (25,085)	$ (11,242)	$ (70,000)
Cash and cash equivalents	$ 100,557	$ 36,045	$ 100,557	$ 126,467	$ 48,555