Regulatory Matters: Winter Storm Uri (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Public Utilities, General Disclosures [Line Items]
Regulatory assets	$ 480.1	$ 653.0
Storm Costs
Public Utilities, General Disclosures [Line Items]
Regulatory assets	$ 199.6	348.0
Regulatory Asset, Amortization Period	2 years 2 months 12 days
Deferred gas cost adjustments
Public Utilities, General Disclosures [Line Items]
Regulatory assets	$ 4.1	$ 12.2