Employee Benefit Plans Net Periodic Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Plan [Member]
Service cost	$ 12,994	$ 11,116	$ 9,637
Interest cost	18,759	22,840	26,488
Expected return on plan assets	27,061	26,162	25,443
Amortization of prior service cost (credit)	0	0	0
Recognized actuarial loss (gain)	(6,536)	(5,028)	(6,544)
Settlement loss recognized(1)	11,291	0	198
Net Periodic Benefit Cost (Credit)	22,519	12,822	17,424
Regulatory deferral of net periodic benefit cost(2)	(13,308)	(2,100)	(7,510)
Previously deferred costs recognized(2)	0	71	728
Amount Recognized in Income	9,211	10,793	10,642
Other Pension, Postretirement and Supplemental Plans [Member]
Service cost	407	370	331
Interest cost	327	492	609
Expected return on plan assets	919	983	869
Amortization of prior service cost (credit)	(1,835)	(1,882)	(1,882)
Recognized actuarial loss (gain)	898	61	96
Settlement loss recognized(1)	0	390	390
Net Periodic Benefit Cost (Credit)	(2,918)	(1,674)	(1,517)
Regulatory deferral of net periodic benefit cost(2)	0	0	0
Previously deferred costs recognized(2)	709	861	931
Amount Recognized in Income	(2,209)	(813)	(586)
Net Periodic Costs [Member] | Pension Plan [Member]
Operating and maintenance	(313)	9,016	2,125
Other income (expense), net	9,524	1,777	8,517
Amount Recognized in Income	9,211	10,793	10,642
Net Periodic Costs [Member] | Other Pension, Postretirement and Supplemental Plans [Member]
Operating and maintenance	407	370	331
Other income (expense), net	(2,616)	(1,183)	(917)
Amount Recognized in Income	$ (2,209)	$ (813)	$ (586)