Pension Plan and Employee Benefits - Amounts Recognized in Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
PENSION BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Net actuarial (gain) loss occurring during period	$ (6,310)	$ 17,082
Net actuarial loss (gain) amortized during period	0	0
Net actuarial loss	58,089	64,399
OTHER BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Net actuarial (gain) loss occurring during period	(1,964)	5,110
Net actuarial loss (gain) amortized during period	653	(45)
Net actuarial loss	9,685	13,103
SERP BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Net actuarial (gain) loss occurring during period	(2,814)	(345)
Net actuarial loss (gain) amortized during period	58	63
Prior service credit amortized during period	(215)	(215)
Net actuarial loss	4,948	7,819
Prior service credit	$ (870)	$ (1,085)