Regulatory and Rate Matters - Schedule of Transmission Cost of Service Rates (Details) - PUCT - TNMP - USD ($) $ in Millions	Mar. 25, 2022	Sep. 20, 2021	Mar. 12, 2021
Public Utilities, General Disclosures [Line Items]
Approved Increase in Rate Base	$ 95.6	$ 41.2	$ 112.6
Annual Increase in Revenue	$ 14.2	$ 6.3	$ 14.1

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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