FAIR VALUE MEASUREMENTS (Tables)

12 Months Ended

Dec. 31, 2020

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value on a Recurring Basis

Assets and liabilities measured at fair value on a recurring basis for PG&E Corporation and the Utility are summarized below.  Assets held in rabbi trusts are held by PG&E Corporation and not the Utility.

	Fair Value Measurements
	At December 31, 2020
(in millions)	Level 1		Level 2		Level 3		Netting (1)		Total
Assets:
Short-term investments	$	470	$	—	$	—	$	—	$	470
Nuclear decommissioning trusts
Short-term investments	27		—		—		—		27
Global equity securities	2,398		—		—		—		2,398
Fixed-income securities	924		835		—		—		1,759
Assets measured at NAV	—		—		—		—		25
Total nuclear decommissioning trusts (2)	3,349		835		—		—		4,209
Price risk management instruments (Note 10)
Electricity	—		2		166		2		170
Gas	—		1		—		113		114
Total price risk management instruments	—		3		166		115		284
Rabbi trusts
Fixed-income securities	—		106		—		—		106
Life insurance contracts	—		79		—		—		79
Total rabbi trusts	—		185		—		—		185
Long-term disability trust
Short-term investments	9		—		—		—		9
Assets measured at NAV	—		—		—		—		158
Total long-term disability trust	9		—		—		—		167
TOTAL ASSETS	$	3,828	$	1,023	$	166	$	115	$	5,315
Liabilities:
Price risk management instruments (Note 10)
Electricity	$	—	$	1	$	238	$	(25)	$	214
Gas	—		3		—		—		3
TOTAL LIABILITIES	$	—	$	4	$	238	$	(25)	$	217

(1) Includes the effect of the contractual ability to settle contracts under master netting agreements and cash collateral.

(2) Represents amount before deducting $671 million, primarily related to deferred taxes on appreciation of investment value. 

	Fair Value Measurements
	At December 31, 2019
(in millions)	Level 1		Level 2		Level 3		Netting (1)		Total
Assets:
Short-term investments	$	1,323	$	—	$	—	$	—	$	1,323
Nuclear decommissioning trusts
Short-term investments	6		—		—		—		6
Global equity securities	2,086		—		—		—		2,086
Fixed-income securities	862		728		—		—		1,590
Assets measured at NAV	—		—		—		—		21
Total nuclear decommissioning trusts (2)	2,954		728		—		—		3,703
Price risk management instruments (Note 10)
Electricity	—		2		161		(11)		152
Gas	—		3		—		3		6
Total price risk management instruments	—		5		161		(8)		158
Rabbi trusts
Fixed-income securities	—		100		—		—		100
Life insurance contracts	—		73		—		—		73
Total rabbi trusts	—		173		—		—		173
Long-term disability trust
Short-term investments	10		—		—		—		10
Assets measured at NAV	—		—		—		—		156
Total long-term disability trust	10		—		—		—		166
TOTAL ASSETS	$	4,287	$	906	$	161	$	(8)	$	5,523
Liabilities:
Price risk management instruments (Note 10)
Electricity	1		2		156		(13)		146
Gas	—		2		—		(1)		1
TOTAL LIABILITIES	$	1	$	4	$	156	$	(14)	$	147

(1) Includes the effect of the contractual ability to settle contracts under master netting agreements and cash collateral.

(2) Represents amount before deducting $530 million, primarily related to deferred taxes on appreciation of investment value.

Uncertainty Analysis

	Fair Value at
(in millions)	At December 31, 2020				Valuation Technique	Unobservable Input
Fair Value Measurement	Assets		Liabilities				Range (1)/Weighted-Average Price (2)
Congestion revenue rights	$	153	$	74	Market approach	CRR auction prices	$ (320.25) - 320.25 / 0.30
Power purchase agreements	$	13	$	164	Discounted cash flow	Forward prices	$ 12.56 - 148.30 / 35.52

(1) Represents price per megawatt-hour.

(2) Unobservable inputs were weighted by the relative fair value of the instruments.

	Fair Value at
(in millions)	At December 31, 2019				Valuation Technique	Unobservable Input
Fair Value Measurement	Assets		Liabilities				Range (1)/Weighted-Average Price (2)
Congestion revenue rights	$	140	$	44	Market approach	CRR auction prices	$ (20.20) - 20.20 / 0.28
Power purchase agreements	$	21	$	112	Discounted cash flow	Forward prices	$ 11.77 - 59.38 / 33.62

(1) Represents price per megawatt-hour.

(2) Unobservable inputs were weighted by the relative fair value of the instruments.

Level 3 Reconciliation

The following table presents the reconciliation for Level 3 price risk management instruments for the years ended December 31, 2020 and 2019, respectively:

	Price Risk Management Instruments
(in millions)	2020		2019
Asset (liability) balance as of January 1	$	5	$	95
Net realized and unrealized gains:
Included in regulatory assets and liabilities or balancing accounts (1)	(77)		(90)
Asset (liability) balance as of December 31	$	(72)	$	5

(1) The costs related to price risk management activities are fully passed through to customers in rates. Accordingly, unrealized gains and losses are deferred in regulatory liabilities and assets and net income is not impacted.

Carrying Amount and Fair Value of Financial Instruments

The carrying amount and fair value of PG&E Corporation’s and the Utility’s long-term debt instruments were as follows (the table below excludes financial instruments with carrying values that approximate their fair values):

	At December 31,
	2020				2019
(in millions)	Carrying Amount		Level 2 Fair Value		Carrying Amount(1)		Level 2 Fair Value(1)(2)
Debt (Note 5)
PG&E Corporation	$	1,901	$	2,175	$	—	$	—
Utility	29,664		32,632		1,500		1,500

(1) On January 29, 2019 PG&E Corporation and the Utility filed for Chapter 11 protection. Debt held by PG&E Corporation became debt subject to compromise and is valued at the allowed claim amount. For more information, see Note 2 and Note 5.

(2) The fair value of the Utility pre-petition debt was $17.9 billion as of December 31, 2019. For more information, see Note 2 and Note 5.

Schedule of Unrealized Gains (Losses) Related to Available-for-sale Investments

The following table provides a summary of equity securities and available-for-sale debt securities:

(in millions)	Amortized Cost		Total Unrealized Gains		Total Unrealized Losses		Total Fair Value
As of December 31, 2020
Nuclear decommissioning trusts
Short-term investments	$	27	$	—	$	—	$	27
Global equity securities	543		1,881		(1)		2,423
Fixed-income securities	1,610		152		(3)		1,759
Total (1)	$	2,180	$	2,033	$	(4)	$	4,209
As of December 31, 2019
Nuclear decommissioning trusts
Short-term investments	$	6	$	—	$	—	$	6
Global equity securities	500		1,609		(2)		2,107
Fixed-income securities	1,505		89		(4)		1,590
Total (1)	$	2,011	$	1,698	$	(6)	$	3,703

(1) Represents amounts before deducting $671 million and $530 million at December 31, 2020 and 2019, respectively, primarily related to deferred taxes on appreciation of investment value.

Schedule of Long Term Debt Repayments

The fair value of fixed-income securities by contractual maturity is as follows:

	As of
(in millions)	December 31, 2020
Less than 1 year	$	50
1–5 years	475
5–10 years	403
More than 10 years	831
Total maturities of fixed-income securities	$	1,759

Schedule of Activity for Debt and Equity Securities

The following table provides a summary of activity for the fixed-income and equity securities:

(in millions)	2020		2019		2018
Proceeds from sales and maturities of nuclear decommissioning investments	$	1,518	$	956	$	1,412
Gross realized gains on securities	159		69		54
Gross realized losses on securities	(41)		(14)		(24)