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PENSION AND RETIREMENT PLANS - Components of net periodic cost (benefit) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022
EMPLOYEE BENEFIT PLANS |  |  |  |
Settlement loss |  |  | $ 2,277 |
Retirement Income Plan |  |  |  |
EMPLOYEE BENEFIT PLANS |  |  |  |
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] | Selling, General and Administrative Expense | Selling, General and Administrative Expense | Selling, General and Administrative Expense | Selling, General and Administrative Expense
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration] | Selling, General and Administrative Expense | Selling, General and Administrative Expense | Selling, General and Administrative Expense | Selling, General and Administrative Expense
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Settlement Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] | Selling, General and Administrative Expense | Selling, General and Administrative Expense | Selling, General and Administrative Expense | Selling, General and Administrative Expense
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] | Selling, General and Administrative Expense | Selling, General and Administrative Expense | Selling, General and Administrative Expense | Selling, General and Administrative Expense
Retirement Income Plan | RPC | Affiliated Entity |  |  |  |
EMPLOYEE BENEFIT PLANS |  |  |  |
Interest cost |  | $ 34 | $ 4 | $ 100
Amortization of net losses |  | 28 | 22 | 84
Settlement loss |  |  | 2,277 |
Net periodic cost |  | $ 62 | $ 2,303 | $ 184

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