Retirement Plans, Components of Net Pension Cost for the Retirement Account Plan Tables (Details) - RAP - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Net period benefit cost for the pension and postretirement plans
Defined Benefit Plan, Service Cost	$ 3,027	$ 3,189	$ 3,670
Defined Benefit Plan, Interest Cost	11,173	10,887	7,152
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(34,599)	(32,862)	(26,903)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(215)	(250)	(250)
Defined Benefit Plan, Amortization of Gain (Loss)	0	0	658
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Total	$ (20,614)	$ (19,037)	$ (15,673)