Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2021

Fair Value of Financial Instruments [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

The Company’s financial assets and liabilities whose values were recognized at fair value in the Company’s condensed consolidated balance sheets are as follows by level within the fair value hierarchy (in millions):

	As of September 30, 2021
	Level 1		Level 2		Level 3		Other(2)		Total
Assets:
Cash equivalents	$	42	$	—	$	—	$	—	$	42
Nuclear decommissioning trust: (1)
Debt securities:
Domestic government	10		8		—		—		18
Corporate credit	—		13		—		—		13
Money market funds measured at NAV (2)	—		—		—		12		12
Non-qualified benefit plan trust: (3)
Debt securities—domestic government	—		—		—		—		—
Money market funds	2		—		—		—		2
Equity securities	7		—		—		—		7
Price risk management activities: (1) (4)
Electricity	—		31		12		—		43
Natural gas	—		205		24		—		229
	$	61	$	257	$	36	$	12	$	366
Liabilities:
Price risk management activities: (1) (4)
Electricity	$	—	$	36	$	90	$	—	$	126
Natural gas	—		2		—		—		2
	$	—	$	38	$	90	$	—	$	128

(1)Activities are subject to regulation, with certain gains and losses deferred pursuant to regulatory accounting and included in Regulatory assets or Regulatory liabilities as appropriate.

(2)Assets are measured at NAV as a practical expedient and not subject to hierarchy level classification disclosure.

(3)Excludes insurance policies of $35 million, which are recorded at cash surrender value.

(4)For further information, see Note 5, Risk Management.

	As of December 31, 2020
	Level 1		Level 2		Level 3		Other (2)		Total
Assets:
Cash equivalents	$	255	$	—	$	—	$	—	$	255
Nuclear decommissioning trust: (1)
Debt securities:
Domestic government	9		11		—		—		20
Corporate credit	—		13		—		—		13
Money market funds measured at NAV (2)	—		—		—		12		12
Non-qualified benefit plan trust: (3)
Debt securities—domestic government	1		—		—		—		1
Money market funds	1		—		—		—		1
Equity securities	7		—		—		—		7
Price risk management activities: (1) (4)
Electricity	—		4		4		—		8
Natural gas	—		36		1		—		37
	$	273	$	64	$	5	$	12	$	354
Liabilities:
Price risk management activities: (1) (4)
Electricity	$	—	$	5	$	141	$	—	$	146
Natural gas	—		4		1		—		5
	$	—	$	9	$	142	$	—	$	151

(1)Activities are subject to regulation, with certain gains and losses deferred pursuant to regulatory accounting and included in Regulatory assets or Regulatory liabilities as appropriate.

(2)Assets are measured at NAV as a practical expedient and not subject to hierarchy level classification disclosure.

(3)Excludes insurance policies of $33 million, which are recorded at cash surrender value.

(4)For further information, see Note 5, Risk Management.

Fair Value Option, Disclosures [Table Text Block]

Quantitative information regarding the significant, unobservable inputs used in the measurement of Level 3 assets and liabilities from price risk management activities is presented below:

	Fair Value				Valuation Technique	Significant Unobservable Input	Price per Unit
Commodity Contracts	Assets		Liabilities				Low		High		Weighted Average
	(in millions)
As of September 30, 2021
Electricity physical forwards	$	4	$	90	Discounted cash flow	Electricity forward price (per MWh)	$	15.00	$	127.00	$	47.86
Natural gas financial swaps	24		—		Discounted cash flow	Natural gas forward price (per Decatherm)	2.21		8.12		3.23
Electricity financial futures	8		—		Discounted cash flow	Electricity forward price (per MWh)	26.50		71.00		56.45
	$	36	$	90
As of December 31, 2020
Electricity physical forwards	$	—	$	141	Discounted cash flow	Electricity forward price (per MWh)	$	11.17	$	51.18	$	29.74
Natural gas financial swaps	1		1		Discounted cash flow	Natural gas forward price (per Decatherm)	1.52		4.33		2.29
Electricity financial futures	4		—		Discounted cash flow	Electricity forward price (per MWh)	8.78		58.42		43.71
	$	5	$	142

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

Changes in the fair value of net liabilities from price risk management activities (net of assets from price risk management activities) classified as Level 3 in the fair value hierarchy were as follows (in millions):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Balance as of the beginning of the period	$	58	$	151	$	137	$	97
Net realized and unrealized losses/(gains)*	11		(17)		(72)		39
Transfers from Level 3 to Level 2	(15)		—		(11)		(2)
Balance as of the end of the period	$	54	$	134	$	54	$	134

* Both realized and unrealized losses/(gains), of which unrealized portion are offset by the effects of regulatory accounting until settlement of the underlying transactions, are recorded in Revenues, net or Purchased power and fuel expense in the condensed consolidated statements of income and comprehensive income. Includes $2 million in net realized losses and $5 million in net realized gains for the three-month periods ended September 30, 2021 and September 30, 2020, respectively. For the nine-month periods ended September 30, 2021 and September 30, 2020, includes $4 million in net realized losses and $8 million in net realized gains, respectively.