Derivatives (Gains And Losses On Derivative Instruments) (Detail) (PGE Corporation And Utility [Member], USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
PGE Corporation And Utility [Member]
Unrealized gain/(loss) - regulatory assets and liabilities	$ 219	[1]	$ 21	[1]	$ 165	[1]	$ 158	[1]
Realized gain/(loss) - cost of electricity	(125)	[2]	(122)	[2]	(275)	[2]	(258)	[2]
Realized gain/(loss) - cost of natural gas	(5)	[2]	(6)	[2]	(27)	[2]	(61)	[2]
Total commodity risk instruments	$ 89		$ (107)		$ (137)		$ (161)

[1] Unrealized gains and losses on commodity risk-related derivative instruments are recorded to regulatory assets or liabilities, rather than being recorded to the Condensed Consolidated Statements of Income. These amounts exclude the impact of cash collateral postings.

[2] These amounts are fully passed through to customers in rates. Accordingly, net income was not impacted by realized amounts on these instruments.