|
Consolidated Balance Sheets (Parenthetical) (USD $)
|
Dec. 31, 2013
|
Dec. 31, 2012
|
|---|---|---|
| Stockholders' equity: | ||
| Preferred stock, par value (in dollars per share) | $ 0.001 | $ 0.001 |
| Preferred stock, shares authorized (in shares) | 15,000,000 | 15,000,000 |
| 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, shares authorized (in shares) | 100,000,000 | 100,000,000 |
| Common stock, shares issued (in shares) | 37,036,996 | 36,272,550 |
| Common stock, shares outstanding (in shares) | 36,624,043 | 35,869,392 |
| Treasury stock ( in shares) | 412,953 | 403,158 |