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Share-Based Compensation - Stock Option Plans (Details) $ / shares in Units, $ in Thousands | 12 Months Ended
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Dec. 31, 2019 USD ($) item $ / shares shares | Dec. 31, 2018 USD ($) $ / shares shares | Dec. 31, 2017 USD ($) $ / shares shares | Dec. 31, 2016 USD ($)
Share-based compensation disclosures |  |  |  |
Share-based compensation expense | $ | $ 24,700 | $ 26,400 | $ 31,900 |
Liability related to awards | $ | 97,003 | 92,358 |  |
Restricted Stock |  |  |  |
Share-based compensation disclosures |  |  |  |
Share-based compensation expense | $ | $ 24,500 | $ 26,000 | $ 31,400 |
Number of types of performance share awards | item | 2 |  |  |
Option to purchase common stock available for grant | 7,700,000 |  |  |
Shares awarded during period | 3,265,000 |  |  |
Options |  |  |  |
Forfeited (in shares) | (521,000) |  |  |
Weighted Average Exercise Price |  |  |  |
Forfeited (in dollars per share) | $ / shares | $ 6.06 |  |  |
Restricted Stock | Employees and Director |  |  |  |
Share-based compensation disclosures |  |  |  |
Shares awarded during period | 3,264,925 | 2,392,486 | 1,130,304 |
Aggregate value of restricted stock awards at date of grant | $ | $ 10,600 | $ 16,600 | $ 14,500 |
Fair value of awards vested | $ | $ 4,100 | $ 8,700 | $ 19,200 |
Restricted Stock | Maximum |  |  |  |
Share-based compensation disclosures |  |  |  |
Vesting period of shares | 5 years |  |  |
Restricted Stock | Maximum | Employees and Director |  |  |  |
Share-based compensation disclosures |  |  |  |
Vesting period of shares | 4 years | 4 years | 4 years |
Restricted Stock Based on Performance Conditions |  |  |  |
Share-based compensation disclosures |  |  |  |
Shares awarded during period | 2,413,000 |  |  |
Fair value of awards vested | $ |  | $ 7,500 | $ 7,000 | $ 7,100
Restricted Stock Based on Performance Conditions | Executive Officer |  |  |  |
Share-based compensation disclosures |  |  |  |
Vesting period of shares | 3 years | 3 years | 3 years |
Total fair value of option vested during the period | $ | $ 2,500 | $ 4,800 | $ 7,100 |
Shares awarded during period | 2,412,631 | 1,009,948 | 461,919 |
Liability related to awards | $ | $ 2,400 | $ 2,200 |  |
Restricted Stock Based on Market Conditions |  |  |  |
Share-based compensation disclosures |  |  |  |
Vesting period of shares | 3 years | 3 years | 3 years |
Shares awarded during period | 2,609,561 | 1,058,158 | 397,692 |
Aggregate value of restricted stock awards at date of grant | $ | $ 3,700 | $ 5,100 | $ 4,400 |
Assumptions used to value grant date fair value |  |  |  |
Risk free interest rate (as a percent) | 2.48% | 2.02% | 1.62% |
Expected volatility (as a percent) | 70.00% | 57.00% | 55.00% |
Closing stock price at grant date (in dollars per share) | $ / shares | $ 2.19 | $ 6.87 | $ 16.81 |
Expected term (in years) | 3 years | 3 years | 3 years |
Key Officer Director and Managerial Employee Stock Options |  |  |  |
Share-based compensation disclosures |  |  |  |
Option to purchase common stock available for grant | 8,500,000 | 15,200,000 |  |
Exercise period | 10 years |  |  |
Total fair value of option vested during the period | $ | $ 200 | $ 400 | $ 500 |
Options |  |  |  |
Options outstanding at the beginning of the period (in shares) | 3,776,000 |  |  |
Granted (in shares) | 138,000 | 171,124 |  |
Exercised (in shares) | 0 | 0 |  |
Surrendered (in shares) | (2,269,000) |  |  |
Forfeited (in shares) | (15,000) |  |  |
Options outstanding at the end of the period (in shares) | 1,630,000 | 3,776,000 |  |
Options exercisable at the end of the period (in shares) | 1,630,000 |  |  |
Weighted Average Exercise Price |  |  |  |
Options outstanding at the beginning of the period (in dollars per share) | $ / shares | $ 11.36 |  |  |
Granted (in dollars per share) | $ / shares | 2.60 |  |  |
Surrendered (in dollars per share) | $ / shares | 9.83 |  |  |
Forfeited (in dollars per share) | $ / shares | 9.18 |  |  |
Options outstanding at the end of the period (in dollars per share) | $ / shares | 12.77 | $ 11.36 |  |
Options exercisable at the end of the period (in dollars per share) | $ / shares | $ 12.77 |  |  |
Weighted Average Remaining Contractual Term |  |  |  |
Options outstanding at the end of the period | 4 years 4 months 13 days |  |  |
Options exercisable at the end of the period | 4 years 4 months 13 days |  |  |
Aggregate Intrinsic Value |  |  |  |
Options outstanding at the end of the period (in dollars) | $ | $ 119 |  |  |
Options exercisable at the end of the period (in dollars) | $ | $ 119 |  |  |
Assumptions used to value grant date fair value |  |  |  |
Granted (in dollars per share) | $ / shares | $ 1.07 | $ 1.75 | $ 2.86 |
Risk free interest rate (as a percent) | 1.79% | 2.59% | 1.85% |
Dividend yield (as a percent) | 1.65% | 3.03% | 2.94% |
Expected volatility (as a percent) | 57.59% | 57.11% | 50.82% |
Expected term (in years) | 4 years | 4 years | 4 years |
Key Officer Director and Managerial Employee Stock Options | Employees Executives And Directors |  |  |  |
Share-based compensation disclosures |  |  |  |
Vesting period of shares | 4 years | 4 years | 4 years |
Options |  |  |  |
Granted (in shares) | 137,954 | 171,124 | 124,271 |

X
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