Stock-Based Incentive Plans Nonvested Restricted Stock Units (Details) - $ / shares |
12 Months Ended | |
|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Share-based Compensation Arrangement by Share-based Payment Award | ||
| Share-based Awards, Restricted Stock Units, Vested Oustanding | 80,000 | |
| Share-based Compensation Arrangement Restricted Stock Units, Nonvested | 14,000 | 35,000 |
| Share-based Compensation Arrangement by Share-based Payment Award, Restricted Stock Units, Nonvested, Weighted Average Grant Date Fair Value | $ 16.27 | $ 15.78 |
| Share-based Compensation Arrangement by Share-based Payment Award, Restricted Stock Units, Grants in Period | (21,000) | |
| Granted | 138,000 | |
| Nonvested at December 31, 2016 | 333,000 | 829,000 |
| Granted, weighted average grant date fair value | $ 3.12 | |
| Vested, weighted average grant date fair value | 15.43 | |
| Nonvested, weighted average grant date fair value at December 31, 2016 | 8.90 | $ 14.41 |
| Vested outstanding, weighted average grant date fair value | $ 20.99 | |