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EMPLOYEE BENEFIT PLANS - Fair Value of Plan Assets (Details) - Defined benefit pension plan - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | --- | ---
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | $ 100,969 | $ 91,567 | $ 75,823
Cash And Cash Equivalents | Quoted Prices In Active Markets For Identical Assets (Level 1) |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | 3,888 | 2,958 |
Equities - Global | Net asset value per share |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | 17,549 | 10,028 |
Equities - United States | Net asset value per share |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | 31,835 | 26,812 |
Equities - United States futures | Net asset value per share |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | (2,616) |  |
Equities - International developed markets | Net asset value per share |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | 8,920 | 10,528 |
Equities - International developed markets futures | Net asset value per share |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | (4,921) |  |
Equities - International emerging markets | Net asset value per share |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | 6,600 | 8,410 |
Equities - International emerging markets futures | Net asset value per share |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | (975) |  |
Fixed income - Investment grade | Net asset value per share |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | 25,703 | 26,186 |
Fixed income - High yield | Net asset value per share |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | 10,056 |  |
Fixed income - Emerging markets | Net asset value per share |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | 2,664 |  |
Fixed income - Futures | Net asset value per share |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | (1,265) |  |
Real estate | Net asset value per share |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets | $ 3,531 | 4,355 |
Pension Plan assets - Other | Net asset value per share |  |  |
Employee Benefit Plans |  |  |
Defined benefit plan, fair value of plan assets |  | $ 2,290 |

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