PENSION PLANS. (Details 4) - Postretirement Plan [Member] $ in Thousands  | 
 Dec. 31, 2018  
USD ($) 
 | 
|---|---|
| 2019 | $ 320 | 
| 2020 | 320 | 
| 2021 | 370 | 
| 2022 | 360 | 
| 2023 | 390 | 
| 2024-28 | 2,350 | 
| Total expected benefit payments | $ 4,110 | 
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- Definition Total expected benefit payments No definition available. 
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- Definition Amount of benefits for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following latest fiscal year. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of benefits for defined benefit plan expected to be paid in next fiscal year following latest fiscal year. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of benefits for defined benefit plan expected to be paid in fifth fiscal year following latest fiscal year. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of benefits for defined benefit plan expected to be paid in fourth fiscal year following latest fiscal year. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of benefits for defined benefit plan expected to be paid in third fiscal year following latest fiscal year. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of benefits for defined benefit plan expected to be paid in second fiscal year following latest fiscal year. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Details 
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