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STOCKHOLDERS' EQUITY - Reclass (Details) - USD ($) $ in Thousands | 6 Months Ended
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Jun. 30, 2021 | Jun. 30, 2020
Unrecognized Net Periodic Benefit Credit |  |
Significant reclassifications out of accumulated other comprehensive loss by component |  |
Total, pre-tax | $ 269 | $ 204
Tax benefit (expense) | (69) | (53)
Total, net of tax | 200 | 151
Amortization of net actuarial gain |  |
Significant reclassifications out of accumulated other comprehensive loss by component |  |
Total, pre-tax | $ 269 | 293
Pension settlement expense, including termination expense |  |
Significant reclassifications out of accumulated other comprehensive loss by component |  |
Total, pre-tax |  | $ (89)

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