Stock-Based Compensation (Stock-Based Compensation Expense) (Details) - USD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2016 |
Mar. 31, 2015 |
|
| Schedule of stock-based compensation expense | ||
| Stock-based compensation | $ 1,389 | $ 1,285 |
| Stock options [Member] | ||
| Schedule of stock-based compensation expense | ||
| Stock-based compensation | 304 | 248 |
| Restricted Stock Units (RSUs) [Member] | ||
| Schedule of stock-based compensation expense | ||
| Stock-based compensation | 574 | 792 |
| Performance stock units [Member] | ||
| Schedule of stock-based compensation expense | ||
| Stock-based compensation | 511 | 245 |
| Research and development [Member] | ||
| Schedule of stock-based compensation expense | ||
| Stock-based compensation | 220 | 291 |
| Selling, general and administrative [Member] | ||
| Schedule of stock-based compensation expense | ||
| Stock-based compensation | $ 1,169 | $ 994 |