Employee Benefit Plans Net Periodic Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Plan [Member]
Service cost	$ 10,223	$ 12,994	$ 11,116
Interest cost	18,787	18,759	22,840
Expected return on plan assets	24,173	27,061	26,162
Amortization of prior service cost (credit)	0	0	0
Recognized actuarial loss (gain)	(383)	(6,536)	(5,028)
Settlement loss recognized(1)	0	11,291	0
Net Periodic Benefit Cost (Credit)	5,220	22,519	12,822
Regulatory deferral of net periodic benefit cost(2)	2,307	(13,308)	(2,100)
Previously deferred costs recognized(2)	0	0	71
Net Periodic Benefit Cost Recognized	7,527	9,211	10,793
Other Pension, Postretirement and Supplemental Plans [Member]
Service cost	351	407	370
Interest cost	359	327	492
Expected return on plan assets	1,047	919	983
Amortization of prior service cost (credit)	(1,891)	(1,835)	(1,882)
Recognized actuarial loss (gain)	897	898	61
Settlement loss recognized(1)	0	0	390
Net Periodic Benefit Cost (Credit)	(3,125)	(2,918)	(1,674)
Regulatory deferral of net periodic benefit cost(2)	0	0	0
Previously deferred costs recognized(2)	292	709	861
Net Periodic Benefit Cost Recognized	$ (2,833)	$ (2,209)	$ (813)