Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2017	Dec. 31, 2016
Consolidated Balance Sheets
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	130,000,000	130,000,000
Common stock, shares issued	50,733,662	49,971,267
Common stock, shares outstanding	50,733,662	49,971,267