Business Segment Information Segment Financial Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Financial Information Abstract
Operating revenues	$ 12,147,412	$ 13,764,237	$ 11,742,896
Asset Impairment Charges	42,679	(163,464)	263,625
Depreciation, Depletion and Amortization	2,051,677	1,985,099	1,990,697
Investment Income, Net	162,726	(75,581)	430,466
Interest expense	1,006,406	912,237	834,694
Income Tax Expense (Benefit)	(690,535)	(38,978)	191,374
Consolidated net income	2,362,310	1,097,138	1,118,719
Total assets	59,703,396	58,595,191	59,454,242
Segment, Expenditure, Addition to Long-Lived Assets	4,746,719	5,396,127	6,422,112
Utility [Member]
Segment Financial Information Abstract
Operating revenues	12,022,944	13,420,804	11,044,674
Asset Impairment Charges	79,962	0	0
Depreciation, Depletion and Amortization	2,045,254	1,941,653	1,823,389
Investment Income, Net	443,751	145,968	442,817
Interest expense	816,643	750,175	692,004
Income Tax Expense (Benefit)	(374,847)	(34,263)	264,209
Consolidated net income	2,510,904	1,398,580	1,488,487
Total assets	63,887,038	61,399,243	59,733,625
Segment, Expenditure, Addition to Long-Lived Assets	4,745,918	5,382,243	6,409,855
Corporate and Other [Member]
Segment Financial Information Abstract
Operating revenues	124,509	343,461	698,251
Asset Impairment Charges	(37,283)	(163,464)	263,625
Depreciation, Depletion and Amortization	6,423	43,446	167,308
Investment Income, Net	18,660	(35,293)	115,273
Interest expense	190,468	162,300	142,693
Income Tax Expense (Benefit)	(315,688)	(4,715)	(72,835)
Consolidated net income	150,385	(115,425)	(242,146)
Total assets	836,598	884,442	1,718,638
Segment, Expenditure, Addition to Long-Lived Assets	801	13,884	12,257
Eliminations [Member]
Segment Financial Information Abstract
Operating revenues	(41)	(28)	(29)
Asset Impairment Charges	0	0	0
Depreciation, Depletion and Amortization	0	0	0
Investment Income, Net	(299,685)	(186,256)	(127,624)
Interest expense	(705)	(238)	(3)
Income Tax Expense (Benefit)	0	0	0
Consolidated net income	(298,979)	(186,017)	(127,622)
Total assets	(5,020,240)	(3,688,494)	(1,998,021)
Segment, Expenditure, Addition to Long-Lived Assets	$ 0	$ 0	$ 0