VIEs (Details) - MW	Sep. 30, 2021	Dec. 31, 2020
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Other Commitments [Line Items]
Generating capacity under long term purchased power agreements (in MW)	1,518	1,518

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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