Stock-based Compensation - Director Deferred Compensation (Details) - Director - shares |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] | |||
| Beginning balance, Director Deferred Stock (in shares) | 135,722 | ||
| New shares deferred (in shares) | 14,722 | ||
| Issued (in shares) | (7,531) | (7,178) | (12,909) |
| Ending balance, Director Deferred Stock (in shares) | 142,913 | 135,722 | |