Consolidated Statements of Changes in Convertible Preferred Stock and Stockholders' Equity (Parenthetical)	Dec. 31, 2016 $ / shares shares
Consolidated statements of changes in convertible preferred stock and stockholders' equity
Series A Convertible preferred stock, par value (in dollars per share) | $ / shares	$ 0.01
Series A Convertible preferred stock, shares authorized | shares	10,000,000
Common stock par value (in dollars per share) | $ / shares	$ 0.01
Common stock, shares authorized | shares	250,000,000