Consolidated Statements of Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (24,338,804)	$ (20,658,846)	$ (35,151,715)
Foreign currency translation adjustment	(22,484)	13,901	(52,485)
Comprehensive loss	$ (24,361,288)	$ (20,644,945)	$ (35,204,200)