Regulatory Matters - MISO Return on Equity Complaint (Details) - FERC [Member]	Sep. 30, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
FERC Authorized Return on Common Equity	10.02%	9.88%
FERC Authorized Return on Equity, Including Incentive Adder	10.52%	10.38%

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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