Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 7,341,116	$ 6,874,629
Less accumulated depreciation and amortization	2,220,206	2,098,298	$ 2,119,074
Net property, plant and equipment	5,120,910	4,776,331	$ 4,506,079
Regulated Operation | Electric | Electric Equipment
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 939,474	938,614
Weighted Average Depreciable Life in Years	48 years
Regulated Operation | Electric | Electric Distribution
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 521,215	489,351
Weighted Average Depreciable Life in Years	47 years
Regulated Operation | Electric | Electric Transmission
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 639,999	616,611
Weighted Average Depreciable Life in Years	65 years
Regulated Operation | Electric | Construction in progress
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 115,103	87,003
Regulated Operation | Electric | Other
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 153,248	145,034
Weighted Average Depreciable Life in Years	15 years
Regulated Operation | Natural gas distribution | Construction in progress
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 70,373	55,759
Regulated Operation | Natural gas distribution | Other
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 246,991	230,299
Weighted Average Depreciable Life in Years	15 years
Regulated Operation | Natural gas distribution | Gas Distribution
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 2,771,540	2,569,921
Weighted Average Depreciable Life in Years	53 years
Regulated Operation | Natural gas distribution | Gas Transmission
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 115,057	104,769
Weighted Average Depreciable Life in Years	54 years
Regulated Operation | Natural gas distribution | Storage
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 42,654	42,318
Weighted Average Depreciable Life in Years	37 years
Regulated Operation | Natural gas distribution | General
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 215,572	204,993
Weighted Average Depreciable Life in Years	13 years
Regulated Operation | Pipeline | Construction in progress
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 55,832	34,655
Regulated Operation | Pipeline | Other
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 63,867	59,917
Weighted Average Depreciable Life in Years	18 years
Regulated Operation | Pipeline | Gas Transmission
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 1,035,995	951,187
Weighted Average Depreciable Life in Years	46 years
Regulated Operation | Pipeline | Storage
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 57,160	55,383
Weighted Average Depreciable Life in Years	53 years
Nonregulated Operation | Pipeline | Construction in progress
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 1,206	49
Nonregulated Operation | Pipeline | Other
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 4,327	6,950
Weighted Average Depreciable Life in Years	9 years
Nonregulated Operation | Construction services | Other
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 6,718	6,642
Weighted Average Depreciable Life in Years	4 years
Nonregulated Operation | Construction services | Land
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 8,662	8,234
Nonregulated Operation | Construction services | Buildings and improvements
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 52,667	50,776
Weighted Average Depreciable Life in Years	23 years
Nonregulated Operation | Construction services | Machinery, vehicles and equipment
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 191,802	179,459
Weighted Average Depreciable Life in Years	7 years
Nonregulated Operation | Other | Other
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 29,365	34,057
Weighted Average Depreciable Life in Years	7 years
Nonregulated Operation | Other | Land
Property, plant and equipment [Line Items]
Property, plant and equipment	$ 2,289	$ 2,648