Retirement Benefit Plans - Narrative (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Interest credit under cash balance plan	0.03
Employer matching contribution, percent of match, maximum	5.00%
Employees' Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Assumptions used calculating benefit obligation, interest rate to annuitize cash balance account		4.66%
Defined benefit plan, increase in benefit payable (in percent)	3.00%
Defined benefit plan, benefit obligation, increase (decrease) for plan amendment	$ 352
Defined benefit plan, amortization of service cost (in years)	9 years 8 months 12 days	7 years 7 months 20 days
Defined benefit plan, benefit obligation, period increase (decrease)			$ 526
Select Executive Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Assumptions used calculating benefit obligation, interest rate to annuitize cash balance account		5.25%
Defined benefit plan, amortization of service cost (in years)	12 years 6 months	7 years 7 months 20 days
Defined benefit plan, benefit obligation, period increase (decrease)	$ 123	$ 441
Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Assumptions used calculating benefit obligation, interest rate to annuitize cash balance account		5.57%
On or Subsequent to January 1, 2003
Defined Benefit Plan Disclosure [Line Items]
Service credits, percent of eligible salaries	6.00%
Prior to January 1, 2003 | Minimum
Defined Benefit Plan Disclosure [Line Items]
Service credits, percent of eligible salaries	6.00%
Prior to January 1, 2003 | Maximum
Defined Benefit Plan Disclosure [Line Items]
Service credits, percent of eligible salaries	12.00%