Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
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	49,971,267	49,004,674
Common stock, shares outstanding	49,971,267	49,004,674