Commitments and Guarantees Schdule of Long term contracts for purchase of electric power (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) MW	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Priest Rapids and Wanapum [Member]
Long-term Contract for Purchase of Electric Power [Line Items]
Revenue Bonds issued by the Public Utility Districts	$ 1,880
PGE Share of Output	8.60%
PGE Share of Capacity | MW	163
commitment costs	$ 25	$ 21	$ 17
Wells [Member]
Long-term Contract for Purchase of Electric Power [Line Items]
Revenue Bonds issued by the Public Utility Districts	$ 572
PGE Share of Output	16.60%
PGE Share of Capacity | MW	94
commitment costs	$ 23	$ 16	$ 11