EMPLOYEE BENEFIT PLANS - Amounts Recognized in the Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Pension Benefits
Employee benefit plans
Net amount recognized	$ (64,980)	$ (63,321)
Pension Benefits | Noncurrent assets
Employee benefit plans
Net amount recognized	164,350	142,607
Pension Benefits | Accrued benefit costs
Employee benefit plans
Net amount recognized	0	0
Pension Benefits | Accrued benefit liability
Employee benefit plans
Net amount recognized	(97,808)	(84,651)
Pension Benefits | Regulatory liabilities
Employee benefit plans
Net amount recognized	(150,851)	(131,297)
Pension Benefits | Accumulated other comprehensive loss
Employee benefit plans
Net amount recognized	19,329	10,020
Other Benefits
Employee benefit plans
Net amount recognized	4,952	2,673
Other Benefits | Noncurrent assets
Employee benefit plans
Net amount recognized	73,234	46,085
Other Benefits | Accrued benefit costs
Employee benefit plans
Net amount recognized	(1)	(1)
Other Benefits | Accrued benefit liability
Employee benefit plans
Net amount recognized	0	0
Other Benefits | Regulatory liabilities
Employee benefit plans
Net amount recognized	(68,281)	(43,411)
Other Benefits | Accumulated other comprehensive loss
Employee benefit plans
Net amount recognized	$ 0	$ 0