CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares |
Sep. 30, 2019 |
Dec. 31, 2018 |
|---|---|---|
| CONDENSED CONSOLIDATED BALANCE SHEETS | ||
| Preferred stock, par value (in dollars per share) | $ 0.001 | $ 0.001 |
| Preferred stock, share authorized (in shares) | 10,000,000 | 10,000,000 |
| Preferred stock, shares issued (in shares) | 0 | 0 |
| Preferred stock, shares outstanding (in shares) | 0 | 0 |
| Common stock, par value (in dollars per share) | $ 0.001 | $ 0.001 |
| Common stock, share authorized (in shares) | 150,000,000 | 150,000,000 |
| Common stock, shares issued (in shares) | 79,777,733 | 79,234,853 |
| Common stock, shares outstanding (in shares) | 79,777,733 | 79,234,853 |