Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Income Tax Expense (Benefit)	$ 3,909	$ 5,214
Net Income (Loss) Attributable to Parent	14,610	19,115
UTILITY OPERATING REVENUES	407,801	491,386
Depreciation and amortization	80,433	69,852
Interest Expense	43,648	34,843
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	18,519	24,329
Assets	7,016,213	6,181,523	$ 6,181,523
Electric [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	80,433	69,852
Interest Expense	32,377	23,875
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	28,971	35,502
Assets	6,570,826	6,129,581
Other Segments [Member]
Segment Reporting Information [Line Items]
UTILITY OPERATING REVENUES	0	0
Depreciation and amortization	0	0
Interest Expense	11,271	10,968
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	(10,452)	(11,173)
Assets	445,387	51,942
Electricity [Member]
Segment Reporting Information [Line Items]
UTILITY OPERATING REVENUES	$ 407,801	$ 491,386