Pension Plan and Employee Benefits - Amounts Recognized in Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
PENSION BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain occurring during period	$ (58,124)	$ (26,925)
Net actuarial loss amortized during period	12,332	20,739
Net actuarial loss	47,317	117,773
OTHER BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain occurring during period	(10,289)	(81)
Net actuarial loss amortized during period	1,207	1,523
Net actuarial loss	13,705	22,785
SERP BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain occurring during period	(22,097)	(1,932)
Net actuarial loss amortized during period	1,049	1,228
Prior service credit amortized during period	(215)	(215)
Net actuarial loss	8,241	31,526
Prior service credit	$ (1,299)	$ (1,514)