v3.26.1
FAIR VALUE (Tables)
 3 Months Ended
Mar. 31, 2026
Fair Value Disclosures [Abstract]  
Schedule of Cost and Fair Values of Assets and Liabilities The cost and fair values of Tri-State's marketable securities are as follows (dollars in thousands):
March 31, 2026December 31, 2025
CostEstimated
Fair Value		CostEstimated
Fair Value
Marketable securities$10,423 $10,406 $10,337 $10,360 
The cost and fair values of Tri-State's marketable securities are as follows (dollars in thousands):
March 31, 2026December 31, 2025
CostEstimated
Fair Value		CostEstimated
Fair Value
Marketable securities$611 $642 $597 $637 
The principal amounts and fair values of debt are as follows (dollars in thousands):
March 31, 2026December 31, 2025
Principal
Amount		Estimated
Fair Value		Principal
Amount		Estimated
Fair Value
Total long-term debt$3,026,567 $2,878,515 $3,188,697 $3,068,509