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ACCUMULATED OTHER COMPREHENSIVE LOSS - Reclassifications out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] |  |  |  |
Amortization of unrealized gains and losses |  | $ 8,227 | $ 8,004 | $ 4,968
Tax benefit (expense) |  | (18,883) | (14,437) | (14,611)
Realized net (loss) gain on sale of securities |  | (2,510) | (15,976) | (3,819)
Total reclassifications for the period, net of tax |  | 8,434 | (151) | (4,775)
Unrealized gains (losses) |  |  |  |
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] |  |  |  |
Reclassified from accumulated other comprehensive income (loss) |  | (10,737) | (23,980) | (8,787)
Realized net gain (loss) on interest rate swap derivatives |  |  |  |
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] |  |  |  |
Reclassified from accumulated other comprehensive income (loss) |  | 22,042 | 24,544 | 3,638
Net actuarial loss |  |  |  |
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] |  |  |  |
Reclassified from accumulated other comprehensive income (loss) | [1] | (629) | (756) | (895)
Amortization of retirement plans |  |  |  |
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] |  |  |  |
Reclassified from accumulated other comprehensive income (loss) |  | (629) | (756) | (895)
Tax benefit |  | 132 | 159 | 188
Total reclassifications for the period, net of tax |  | (497) | (597) | (707)
Unrealized losses on securities transferred | Reclassification out of accumulated other comprehensive income | Unrealized gains (losses) |  |  |  |
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] |  |  |  |
Amortization of unrealized gains and losses | [2] | (8,227) | (8,004) | (4,968)
Tax benefit (expense) |  | 1,728 | 1,681 | 1,043
Net of tax |  | (6,499) | (6,323) | (3,925)
Unrealized gains and losses on available for sale securities | Reclassification out of accumulated other comprehensive income | Unrealized gains (losses) |  |  |  |
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] |  |  |  |
Tax benefit (expense) |  | 527 | 3,355 | 802
Net of tax |  | (1,983) | (12,621) | (3,017)
Realized net (loss) gain on sale of securities | [3] | (2,510) | (15,976) | (3,819)
Interest rate swap derivatives | Reclassification out of accumulated other comprehensive income | Realized net gain (loss) on interest rate swap derivatives |  |  |  |
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] |  |  |  |
Tax benefit (expense) |  | (4,629) | (5,154) | (764)
Net of tax |  | 17,413 | 19,390 | 2,874
Realized net gain (loss) on interest rate swaps | [4] | $ 22,042 | $ 24,544 | $ 3,638
[1] | These AOCI components are included in the computation of net periodic pension cost (income) presented in “Note 10 – Employee Benefits.”
[2] | Included in interest income on the consolidated statements of income.
[3] | Listed as net gain (loss) on sale of securities AFS on the consolidated statements of income.
[4] | Included in interest expense for FHLB borrowings, other borrowings and deposits on the consolidated statements of income.

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