Employee Benefit Plans Benefit Obligation And Funded Status (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) numberOfParticipants	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Pension Plan [Member]
Change in Benefit Obligation:
Obligation at beginning of period	$ 820,979	$ 735,564
Service cost	12,994	11,116	$ 9,637
Interest cost	18,759	22,840	26,488
Actuarial loss	(28,905)	84,479
Settlements(1)	(93,488)	0
Benefits paid	(33,537)	(33,020)
Benefit Obligation at End of Period	696,802	820,979	735,564
Change in Fair Value of Plan Assets:
Settlements(1)	(93,500)
Amounts Recognized in the Balance Sheet Consist of:
Noncurrent asset	8,297	7,001
Total Assets	8,297	7,001
Current liability	(11,200)	(11,200)
Noncurrent liability	(88,400)	(128,324)
Total Liabilities	(99,600)	(139,524)
Net amount recognized	(91,303)	(132,523)
Amounts recognized in AOCL consist of:
Prior service cost	0	0
Net actuarial gain	0	0
Total	(62,448)	(115,987)
Plans with Benefit Obligations in Excess of Plan Assets [Abstract]
Projected benefit obligation	636,300	757,400
Accumulated benefit obligation	636,300	757,400
Fair value of plan assets(1)	537,900	619,100
Plan Assets used to purchase annuity contract	93,500
Settlement loss recognized(1)	$ 11,291	0	198
Pension Plan, Participants included in Pension Settlement | numberOfParticipants	1,062
Pension Plan [Member] | Pension
Amounts Recognized in Regulatory Assets Consist of:
Prior service credit	$ 0	0
Net actuarial loss	(62,448)	(115,987)
Pension Plan [Member] | Changes Measurement [Member]
Change in Fair Value of Plan Assets:
Fair value of plan assets at beginning of period	688,456	609,000
Return on plan assets	33,868	101,075
Employer contributions	10,200	11,401
Settlements(1)	(93,488)	0
Benefits paid	(33,537)	(33,020)
Fair value of plan assets at end of period	605,499	688,456	609,000
Funded Status	(91,303)	(132,523)
Other Postretirement Benefits Plan [Member]
Change in Benefit Obligation:
Obligation at beginning of period	19,146	20,272
Service cost	407	370
Interest cost	317	492
Actuarial loss	415	123
Settlements(1)	0	(390)
Benefits paid	(2,977)	(2,501)
Benefit Obligation at End of Period	17,308	19,146	20,272
Amounts Recognized in the Balance Sheet Consist of:
Noncurrent asset	11,914	8,436
Total Assets	11,914	8,436
Current liability	(1,575)	(1,712)
Noncurrent liability	(2,358)	(2,774)
Total Liabilities	(3,933)	(4,486)
Net amount recognized	7,981	3,950
Amounts recognized in AOCL consist of:
Prior service cost	(95)	(246)
Net actuarial gain	2,500	(3,246)
Total	5,641	6,360
Other Postretirement Benefits Plan [Member] | Pension
Amounts Recognized in Regulatory Assets Consist of:
Prior service credit	1,870	3,857
Net actuarial loss	1,366	(497)
Other Postretirement Benefits Plan [Member] | Changes Measurement [Member]
Change in Fair Value of Plan Assets:
Fair value of plan assets at beginning of period	23,096	21,479
Return on plan assets	3,349	2,723
Employer contributions	1,821	1,395
Settlements(1)	0	0
Benefits paid	(2,977)	(2,501)
Fair value of plan assets at end of period	25,289	23,096	$ 21,479
Funded Status	$ 7,981	$ 3,950