COMMON STOCK AND SHARE-BASED COMPENSATION (Narrative) (Details) $ / shares in Units, purchaseContract in Thousands, equityUnit in Thousands						1 Months Ended	3 Months Ended	12 Months Ended			72 Months Ended
	Aug. 03, 2020 USD ($) equityUnit shares	Jul. 01, 2020 USD ($) shares	Jun. 25, 2020 USD ($) equityUnit purchaseContract shares	Jun. 07, 2020 USD ($) $ / shares	May 28, 2020	Jul. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares	Dec. 31, 2020 USD ($) shares	Jun. 22, 2020 shares	Mar. 20, 2020 USD ($)
Schedule of Capitalization, Equity [Line Items]
Common stock, shares outstanding (in shares)								1,984,678,673	529,236,741		1,984,678,673
Common stock, shares authorized (in shares)								3,600,000,000	800,000,000		3,600,000,000	3,600,000,000
Preferred stock, shares authorized (in shares)												400,000,000
Equity Units issued | $		$ 9,000,000,000.0	$ 3,970,000,000			$ 9,000,000,000.0		$ 1,304,000,000	$ 0	$ 0
Sale of stock, consideration received on transaction | $				$ 3,250,000,000
Sale of stock, price per share (in dollars per share) | $ / shares				$ 9.50
Sale of stock, number of shares issued in transaction (in shares)		342,100,000
Proceeds from issuance or sale of equity, net | $		$ 5,200,000,000	$ 1,190,000,000
Proceeds from equity backstop commitments and forward stock purchase agreements | $								523,000,000
Sale of stock, redemption of rights, return amount | $	$ 120,500,000
Sale of stock, issuance and delivery, common stock (in shares)	42,300,000
Transfer of shares to Fire Victim Trust (in shares)		477,000,000.0
Transfer of shares to Fire Victim Trust, additional (in shares)	748,415
Equity contribution cash | $								$ 12,900,000,000			$ 12,900,000,000
Percentage of equity security ownership with board of director approval								4.75%			4.75%
Deferred tax asset, litigation adjustment | $							$ 619,000,000
Dividend reinstatement target, amount | $													$ 6,200,000,000
Equity capital structure percentage		52.00%
Equity capital structure, waiver period					5 years
Number of shares issued for LTIP, maximum (in shares)								17,000,000			17,000,000
Shares available for LTIP award (in shares)								29,174,205			29,174,205
Weighted average grant date fair value of granted shares (in dollars per share) | $ / shares								$ 9.25	$ 18.57	$ 40.92
Total fair value | $								$ 31,000,000	$ 42,000,000	$ 41,000,000
Total unrecognized compensation costs | $								$ 6,000,000
Remaining weighted average period								1 year 6 months 29 days
Fire Trust Victim
Schedule of Capitalization, Equity [Line Items]
Transfer of shares to Fire Victim Trust (in shares)		477,000,000
Transfer of shares to Fire Victim Trust, additional (in shares)	748,415
Litigation liability, payment accrual | $									$ 6,750,000,000
Transfer of shares related to litigation settlement, value | $							4,530,000,000
Difference between payment accrual and transfer of shares related to litigation settlement, value | $							$ 2,200,000,000
Minimum
Schedule of Capitalization, Equity [Line Items]
Sale of stock, number of equity units, right to receive	125,000,000
Sale of stock, number of additional units, right to receive (in shares)	12,500,000
Maximum
Schedule of Capitalization, Equity [Line Items]
Sale of stock, number of equity units, right to receive	153,000,000
Sale of stock, number of additional units, right to receive (in shares)	15,300,000
2014 LTIP, Amended
Schedule of Capitalization, Equity [Line Items]
Number of shares issued for LTIP, maximum (in shares)								47,000,000			47,000,000
Stock Options
Schedule of Capitalization, Equity [Line Items]
Granted (in shares)								0
Tax benefit from share based awards | $								$ 0
Weighted-average period								2 years 2 months 12 days
Stock Options | 2014 LTIP
Schedule of Capitalization, Equity [Line Items]
Term of award								10 years
Award vesting period								3 years
Total unrecognized compensation costs | $								$ 500,000			$ 500,000
Weighted average grant date fair value of granted shares (in dollars per share) | $ / shares									$ 3.87
Granted (in shares)								20,065
Restricted stock units
Schedule of Capitalization, Equity [Line Items]
Award vesting period											3 years
Tax detriment | $								$ 19,000,000
Performance shares
Schedule of Capitalization, Equity [Line Items]
Award vesting period								3 years
Tax detriment | $								$ 49,000,000
Industry performance period								3 years
Award grant date fair value recognition period								3 years
Performance shares granted (in dollars per share) | $ / shares								$ 9.62	$ 15.39	$ 36.92
Employee service share based compensation nonvested performance shares total compensation cost not yet recognized | $								$ 54,000,000
Common Stock Offering
Schedule of Capitalization, Equity [Line Items]
Sale of stock, number of shares issued in transaction (in shares)			423,400,000
Option to purchase additional stock (in shares)	42,300,000		42,300,000
Equity Units Offering
Schedule of Capitalization, Equity [Line Items]
Sale of stock, number of equity units issued in transaction (in equity units) | equityUnit			14,500
Sale of stock, number of prepaid forward stock purchase contracts issued and sold in transaction (in purchase contracts) | purchaseContract			14,500
Sale of stock, number of prepaid forward stock purchase contracts issued and sold in transaction, additional contracts (in purchase contracts) | purchaseContract			1,450
Option to purchase additional contracts (in equity units) | equityUnit	1,450
Sale of stock, number of equity units issued and sold in transaction, additional (in equity units) | equityUnit	1,450
Common Stock Underwriters
Schedule of Capitalization, Equity [Line Items]
Sale of stock, number of shares issued and sold in transaction (in shares)			423,400,000
Equity Units Underwriters
Schedule of Capitalization, Equity [Line Items]
Sale of stock, number of prepaid forward stock purchase contracts issued and sold in transaction (in purchase contracts) | purchaseContract			14,500
PG&E Corporation
Schedule of Capitalization, Equity [Line Items]
Preferred stock, shares authorized (in shares)								400,000,000			400,000,000
Equity Units issued | $								$ 1,304,000,000	$ 0	$ 0
unrecognized compensation cost, period								1 month 28 days
PG&E Corporation | Minimum | Revolving Credit Facility
Schedule of Capitalization, Equity [Line Items]
Debt, ratio of total consolidated debt to consolidated capitalization, loans outstanding balance		150.00%
Debt, ratio of total consolidated debt to consolidated capitalization, cash dividend declared		100.00%
PG&E Corporation | Maximum | Revolving Credit Facility
Schedule of Capitalization, Equity [Line Items]
Debt, ratio of total consolidated debt to consolidated capitalization		70.00%