Retirement, Other Postretirement Benefits, And Defined Contribution Plans Investments Held For Qualified Pension And Other Postretirement Plans Measured At Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash	$ 123,153	$ 2,316
Other pending transactions	11,125	(29,121)
Less: Other postretirement assets included in total investments	(79,360)	(76,033)
Defined Benefit Plan, Plan Assets, Amount	6,993,110	6,854,426
Qualified Pension Plans [Member] | Defined Benefit Plan, Equity Securities, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	16,231	15,756
Qualified Pension Plans [Member] | Defined Benefit Plan, Equity Securities, Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	1,001,169	1,031,213
Qualified Pension Plans [Member] | Defined Benefit Plan, Common Collective Trust
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	3,123,111	2,958,767
Qualified Pension Plans [Member] | U.S. Government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	627,148	731,319
Qualified Pension Plans [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	966,616	1,029,370
Qualified Pension Plans [Member] | Registered Investment Company
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	1,129,070	1,128,107
Qualified Pension Plans [Member] | Other Debt Obligations
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	68,886	56,479
Qualified Pension Plans [Member] | Other Contract
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	5,961	6,253
Qualified Pension Plans [Member] | Defined Benefit Plan Total Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	6,938,192	6,957,264
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Other pending transactions	(25,897)	(21,931)
Plus: Other postretirement assets included in the investments of the qualified pension trust	79,360	76,033
Defined Benefit Plan, Plan Assets, Amount	771,319	737,866	$ 686,262
Other Postretirement Benefits Plan [Member] | Defined Benefit Plan, Common Collective Trust
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	312,594	315,191
Other Postretirement Benefits Plan [Member] | U.S. Government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	152,191	144,102
Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	152,562	147,287
Other Postretirement Benefits Plan [Member] | Registered Investment Company
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	28,450	16,965
Other Postretirement Benefits Plan [Member] | Other Debt Obligations
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	72,059	60,219
Other Postretirement Benefits Plan [Member] | Defined Benefit Plan Total Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	717,856	683,764
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Defined Benefit Plan, Equity Securities, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	16,231	15,756
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Defined Benefit Plan, Equity Securities, Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	1,001,169	1,031,213
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | U.S. Government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Registered Investment Company
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	92,347	81,800
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Other Debt Obligations
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	156
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Other Contract
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 1 [Member] | Qualified Pension Plans [Member] | Defined Benefit Plan Total Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	1,109,747	1,128,925
Fair Value Inputs Level 1 [Member] | Other Postretirement Benefits Plan [Member] | U.S. Government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	62,240	46,498
Fair Value Inputs Level 1 [Member] | Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 1 [Member] | Other Postretirement Benefits Plan [Member] | Registered Investment Company
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	28,450	16,965
Fair Value Inputs Level 1 [Member] | Other Postretirement Benefits Plan [Member] | Other Debt Obligations
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 1 [Member] | Other Postretirement Benefits Plan [Member] | Defined Benefit Plan Total Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	90,690	63,463
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Defined Benefit Plan, Equity Securities, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Defined Benefit Plan, Equity Securities, Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | U.S. Government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	627,148	731,319
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	966,616	1,029,370
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Registered Investment Company
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	3,004	3,076
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Other Debt Obligations
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	68,886	56,323
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Other Contract
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	5,961	6,253
Fair Value Inputs Level 2 [Member] | Qualified Pension Plans [Member] | Defined Benefit Plan Total Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	1,671,615	1,826,341
Fair Value Inputs Level 2 [Member] | Other Postretirement Benefits Plan [Member] | U.S. Government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	89,951	97,604
Fair Value Inputs Level 2 [Member] | Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	152,562	147,287
Fair Value Inputs Level 2 [Member] | Other Postretirement Benefits Plan [Member] | Registered Investment Company
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 2 [Member] | Other Postretirement Benefits Plan [Member] | Other Debt Obligations
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	72,059	60,219
Fair Value Inputs Level 2 [Member] | Other Postretirement Benefits Plan [Member] | Defined Benefit Plan Total Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	314,572	305,110
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Defined Benefit Plan, Equity Securities, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Defined Benefit Plan, Equity Securities, Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | U.S. Government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Registered Investment Company
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Other Debt Obligations
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Other Contract
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 3 [Member] | Qualified Pension Plans [Member] | Defined Benefit Plan Total Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 3 [Member] | Other Postretirement Benefits Plan [Member] | U.S. Government securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 3 [Member] | Other Postretirement Benefits Plan [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 3 [Member] | Other Postretirement Benefits Plan [Member] | Registered Investment Company
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 3 [Member] | Other Postretirement Benefits Plan [Member] | Other Debt Obligations
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	0	0
Fair Value Inputs Level 3 [Member] | Other Postretirement Benefits Plan [Member] | Defined Benefit Plan Total Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Amount	$ 0	$ 0