Stock-based Compensation - Performance Unit Awards - Additional Disclosures (Details) - Performance Unit Awards $ in Millions |
12 Months Ended |
|---|---|
|
Dec. 31, 2016
USD ($)
| |
| Stock-based Compensation | |
| Unrecognized expenses | $ 0.9 |
| Weighted-average remaining recognition period (in years) | 2 years |