Preferred Stock and Stockholders' Equity (Summary of Stock-Based Compensation) (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Non-cash stock-based compensation expense | $ 6,013 | $ 5,201 | $ 5,196 |
| Research And Development Expense | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Non-cash stock-based compensation expense | 839 | 723 | 618 |
| Selling, General And Administrative Expense | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Non-cash stock-based compensation expense | $ 5,174 | $ 4,478 | $ 4,578 |