Business Segment Information (Schedule of Segment Reporting Information, by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Segment Reporting Information [Line Items]
Asset Impairment Charges	$ 0	$ 131,775
Depreciation, Depletion and Amortization	568,872	553,043
Investment Income, Net	33,406	150,697
Interest Expense, Nonoperating	329,791	267,200
Income Tax Expense (Benefit)	100,041	20,994
Assets	66,620,409		$ 64,790,032
Segment, Expenditure, Addition to Long-Lived Assets	1,750,008	1,267,081
Consolidation, Eliminations
Segment Reporting Information [Line Items]
Asset Impairment Charges		0
Depreciation, Depletion and Amortization	0	0
Investment Income, Net	(75,457)	(79,922)
Interest Expense, Nonoperating	(209)	(361)
Income Tax Expense (Benefit)	0	0
Assets	(4,887,107)		(4,882,991)
Segment, Expenditure, Addition to Long-Lived Assets	0	0
Utility [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Asset Impairment Charges		131,775
Depreciation, Depletion and Amortization	567,187	551,489
Investment Income, Net	107,175	225,251
Interest Expense, Nonoperating	267,131	212,148
Income Tax Expense (Benefit)	114,273	34,548
Assets	70,774,423		68,951,564
Segment, Expenditure, Addition to Long-Lived Assets	1,749,817	1,266,823
Corporate Segment and Other Operating Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Asset Impairment Charges		0
Depreciation, Depletion and Amortization	1,685	1,554
Investment Income, Net	1,688	5,368
Interest Expense, Nonoperating	62,869	55,413
Income Tax Expense (Benefit)	(14,232)	(13,554)
Assets	733,093		$ 721,459
Segment, Expenditure, Addition to Long-Lived Assets	$ 191	$ 258