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STOCKHOLDERS' EQUITY - Reclass (Details) - USD ($) $ in Thousands | 9 Months Ended
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Sep. 30, 2021 | Sep. 30, 2020
Unrecognized Net Periodic Benefit Credit |  |
Significant reclassifications out of accumulated other comprehensive loss by component |  |
Total, pre-tax | $ 404 | $ 352
Tax benefit (expense) | (104) | (91)
Total, net of tax | 300 | 261
Amortization of net actuarial gain |  |
Significant reclassifications out of accumulated other comprehensive loss by component |  |
Total, pre-tax | $ 404 | 441
Pension settlement expense, including termination expense |  |
Significant reclassifications out of accumulated other comprehensive loss by component |  |
Total, pre-tax |  | $ (89)

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