Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 9,734,150	$ 9,124,134
Public Utilities, Property, Plant and Equipment, Accumulated Depreciation	(2,611,952)	(2,478,261)
Property, Plant and Equipment, Net	7,122,198	6,645,873
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	$ 24,200	17,400
Minimum [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service	2.70%
Maximum [Member]
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service	3.20%
Regulated Operation
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Accumulated Depreciation	$ (2,611,952)	(2,478,261)
Interest Costs Capitalized	11,800	8,200	$ 5,700
Construction in Progress Expenditures Incurred but Not yet Paid	28,900	33,700	$ 36,200
Regulated Operation | Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment	7,797,444	7,278,542
Regulated Operation | Gas Transmission Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment	771,304	736,229
Regulated Operation | Land, Buildings and Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment	1,066,476	942,677
Regulated Operation | Construction in Progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 98,926	$ 166,686