Winter Storm Uri (Details) - USD ($)		1 Months Ended	4 Months Ended
	Oct. 25, 2022	Feb. 28, 2021	Dec. 31, 2022	Sep. 30, 2022	Mar. 31, 2021
Unusual or Infrequent Item, or Both [Line Items]
Aggregate natural gas purchases		$ 2,300,000,000
Regulatory assets			$ 2,471,810,000	$ 2,605,372,000
Winter Storm Uri incremental costs
Unusual or Infrequent Item, or Both [Line Items]
Regulatory assets			2,125,787,000	$ 2,109,454,000
Winter Storm Uri incremental costs | Winter Storm Uri
Unusual or Infrequent Item, or Both [Line Items]
Regulatory assets			2,100,000,000
Winter Storm Uri incremental costs | Winter Storm Uri | Kansas
Unusual or Infrequent Item, or Both [Line Items]
Regulatory assets			89,000,000
Winter Storm Uri incremental costs | Winter Storm Uri | Texas
Unusual or Infrequent Item, or Both [Line Items]
Regulatory assets			2,021,900,000
Regulatory asset, deferred costs			$ 14,900,000
Extraordinary Gas Cost | Winter Storm Uri | Kansas
Unusual or Infrequent Item, or Both [Line Items]
Regulatory asset, authorized	$ 118,500,000
Regulatory asset, amortization period	12 years
Senior Notes Due 2023
Unusual or Infrequent Item, or Both [Line Items]
Debt instrument, face amount					$ 2,200,000,000