Regulatory and Rate Matters - AMS Reconciliation (Details) $ in Millions	9 Months Ended
Dec. 31, 2018 USD ($)
Texas-New Mexico Power Company
Public Utilities, General Disclosures [Line Items]
Costs of deployment	$ 9.0

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.

No definition available.

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