BANKRUPTCY FILING (Equity Financing) (Details) - USD ($) $ / shares in Units, shares in Millions			1 Months Ended	12 Months Ended
	Jul. 01, 2020	Jun. 25, 2020	Jul. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2020	Aug. 03, 2020	Jun. 30, 2020	Jun. 19, 2020	Mar. 06, 2020
Debt Instrument [Line Items]
Equity Units issued	$ 9,000,000,000.0	$ 3,970,000,000	$ 9,000,000,000.0	$ 1,304,000,000	$ 0	$ 0
Equity backstop commitments, shares (in shares)	119.0
Equity backstop commitments, value	$ 12,000,000,000.0
Backstop commitment premium, expense									$ 1,100,000,000
Share price (in dollar per share)	$ 9.03								$ 8.87
Additional backstop commitment premium, expense							$ 19,000,000		$ 444,000,000
Professional legal fees				34,000,000
Professional non-legal fees				19,000,000
Professional fees				49,000,000
Settlement price (in dollars per share)										$ 9.50
Additional forward stock purchase agreement, expense							$ 8,000,000
Backstop Parties
Debt Instrument [Line Items]
Debt commitment letters, required equity funding											$ 12,000,000,000.0
Forward stock purchase agreement, common stock issues, pro rata (in shares)		50.0
Offerings
Debt Instrument [Line Items]
Equity Units issued				5,750,000,000
Option Amount
Debt Instrument [Line Items]
Equity Units issued		$ 523,000,000
Common Stock Offering
Debt Instrument [Line Items]
Option to purchase additional stock, delivered (in shares)		42.3						42.3
PG&E Corporation
Debt Instrument [Line Items]
Equity Units issued				$ 1,304,000,000	$ 0	$ 0
Forward stock purchase, redemption amount								$ 120,500,000