COMMITMENTS AND CONTINGENCIES - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Operating leases
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other	Other
Other assets: Other	$ 13,387	$ 14,762
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other accrued liabilities	Other accrued liabilities
Other accrued liabilities	$ 962	$ 1,065
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other long-term liabilities	Other long-term liabilities
Other long-term liabilities	$ 12,605	$ 13,838
Total	13,567	14,903
Finance leases
Depreciable plant and equipment	19,087	19,820
Accumulated depreciation and amortization	(14,339)	(14,017)
Net utility plant	$ 4,748	$ 5,803
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Current maturities of long-term debt, net	Current maturities of long-term debt, net
Current maturities of long-term debt, net	$ 844
Current maturities of long-term debt, net		$ 2,555
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Long-term debt, net	Long-term debt, net
Long-term debt, net	$ 3,057	$ 2,675
Total finance lease liabilities	$ 3,901	$ 5,230
Weighted average remaining lease term
Operating leases	112 months	119 months
Finance leases	29 months	32 months
Weighted average discount rate
Operating leases	3.60%	3.50%
Finance leases	5.50%	4.40%