Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2020

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 are as follows by level within the fair value hierarchy (in millions):

	As of September 30, 2020
	Level 1		Level 2		Level 3		Other(2)		Total
Assets:
Cash equivalents	$	228	$	—	$	—	$	—	$	228
Nuclear decommissioning trust: (1)
Debt securities:
Domestic government	8		12		—		—		20
Corporate credit	—		14		—		—		14
Money market funds measured at NAV (2)	—		—		—		13		13
Non-qualified benefit plan trust: (3)
Money market funds	1		—		—		—		1
Equity securities	7		—		—		—		7
Debt securities—domestic government	1		—		—		—		1
Price risk management activities: (1) (4)
Electricity	—		9		2		—		11
Natural gas	—		60		10		—		70
	$	245	$	95	$	12	$	13	$	365
Liabilities:
Price risk management activities: (1) (4)
Electricity	$	—	$	3	$	146	$	—	$	149
Natural gas	—		5		—		—		5
	$	—	$	8	$	146	$	—	$	154

(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 $30 million, which are recorded at cash surrender value.

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

	As of December 31, 2019
	Level 1		Level 2		Level 3		Other (2)		Total
Assets:
Cash equivalents	$	26	$	—	$	—	$	—	$	26
Nuclear decommissioning trust: (1)
Debt securities:
Domestic government	8		16		—		—		24
Corporate credit	—		9		—		—		9
Money market funds measured at NAV (2)	—		—		—		13		13
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	—		9		7		—		16
Natural gas	—		21		1		—		22
	$	43	$	55	$	8	$	13	$	119
Liabilities:
Price risk management activities: (1) (4)
Electricity	—		14		105		—		119
Natural gas	—		12		—		—		12
	$	—	$	26	$	105	$	—	$	131

(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 $29 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, 2020
Electricity physical forwards	$	—	$	144	Discounted cash flow	Electricity forward price (per MWh)	$	12.66	$	43.21	$	29.49
Natural gas financial swaps	10		—		Discounted cash flow	Natural gas forward price (per Decatherm)	1.64		4.77		2.39
Electricity financial futures	2		2		Discounted cash flow	Electricity forward price (per MWh)	16.50		56.00		38.63
	$	12	$	146
As of December 31, 2019
Electricity physical forwards	$	—	$	104	Discounted cash flow	Electricity forward price (per MWh)	$	12.53	$	59.00	$	36.92
Natural gas financial swaps	1		—		Discounted cash flow	Natural gas forward price (per Decatherm)	1.39		3.73		1.90
Electricity financial futures	7		1		Discounted cash flow	Electricity forward price (per MWh)	10.57		66.32		45.11
	$	8	$	105

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,
	2020		2019		2020		2019
Balance as of the beginning of the period	$	151	$	72	$	97	$	88
Net realized and unrealized losses/(gains)*	(17)		30		39		14
Transfers from Level 3 to Level 2	—		(1)		(2)		(1)
Balance as of the end of the period	$	134	$	101	$	134	$	101

* 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 Purchased power and fuel expense in the condensed consolidated statements of income and comprehensive income.