XML 69 R46.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Fair Value Measurements (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2023
Fair Value Disclosures [Abstract] |
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis | Assets and liabilities measured at fair value on a recurring basis consisted of the following at the respective balance sheet dates shown below:
| December 31, 2023 |  | December 31, 2022
| Level 1 |  | Level 2 |  | Level 3 (a) |  | Reclass (b) |  | Total |  | Level 1 |  | Level 2 |  | Level 3 (a) |  | Reclass (b) |  | Total
Assets: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commodity contracts | $ | 2,886 |  |  | $ | 628 |  |  | $ | 630 |  |  | $ | 14 |  |  | $ | 4,158 |  |  | $ | 3,512 |  |  | $ | 789 |  |  | $ | 791 |  |  | $ | 13 |  |  | $ | 5,105 |
Interest rate swaps | — |  |  | 64 |  |  | — |  |  | — |  |  | 64 |  |  | — |  |  | 135 |  |  | — |  |  | — |  |  | 135 |
Nuclear decommissioning trust – equity securities (c) | 638 |  |  | — |  |  | — |  |  | — |  |  | 638 |  |  | 532 |  |  | — |  |  | — |  |  | — |  |  | 532 |
Nuclear decommissioning trust – debt securities (c) | — |  |  | 734 |  |  | — |  |  | — |  |  | 734 |  |  | — |  |  | 658 |  |  | — |  |  | — |  |  | 658 |
Sub-total | $ | 3,524 |  |  | $ | 1,426 |  |  | $ | 630 |  |  | $ | 14 |  |  | 5,594 |  |  | $ | 4,044 |  |  | $ | 1,582 |  |  | $ | 791 |  |  | $ | 13 |  |  | 6,430 |
Assets measured at net asset value (d): |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Nuclear decommissioning trust – equity securities (c) |  |  |  |  |  |  |  |  | 579 |  |  |  |  |  |  |  |  |  |  | 458 |
Total assets |  |  |  |  |  |  |  |  | $ | 6,173 |  |  |  |  |  |  |  |  |  |  | $ | 6,888 |
Liabilities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Commodity contracts | $ | 3,815 |  |  | $ | 1,395 |  |  | $ | 1,674 |  |  | $ | 14 |  |  | $ | 6,898 |  |  | $ | 5,297 |  |  | $ | 933 |  |  | $ | 2,010 |  |  | $ | 13 |  |  | $ | 8,253 |
Interest rate swaps | — |  |  | 48 |  |  | — |  |  | — |  |  | 48 |  |  | — |  |  | 83 |  |  | — |  |  | — |  |  | 83 |
Total liabilities | $ | 3,815 |  |  | $ | 1,443 |  |  | $ | 1,674 |  |  | $ | 14 |  |  | $ | 6,946 |  |  | $ | 5,297 |  |  | $ | 1,016 |  |  | $ | 2,010 |  |  | $ | 13 |  |  | $ | 8,336 |
____________ (a)See table below for description of Level 3 assets and liabilities. (b)Fair values for each level are determined on a contract basis, but certain contracts are in both an asset and a liability position. This reclassification represents the adjustment needed to reconcile to the gross amounts presented on our consolidated balance sheet. (c)The nuclear decommissioning trust investment is included in the investments line in our consolidated balance sheets. See Note 22. (d)The fair value amounts presented in this line are intended to permit reconciliation of the fair value hierarchy to the amounts presented in our consolidated balance sheets. Certain investments measured at fair value using the net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. Net asset value as a practical expedient is the classification used for assets that do not have readily determinable fair values. As of December 31, 2023 and 2022, all of the Retirement Plan assets were measured at fair value using the net asset value per share (or its equivalent) except as noted and consisted of the following:
| December 31,
| 2023 |  | 2022
Asset Category: |  |  |
Interest-bearing cash (a) | $ | — |  |  | $ | 2 |
Cash commingled trusts | 4 |  |  | 4 |
Equity securities: |  |  |
Global equities | 82 |  |  | 80 |
Fixed income securities: |  |  |
Corporate bonds (b) | 82 |  |  | 107 |
Government bonds | 54 |  |  | 44 |
Other (c) | 18 |  |  | 24 |
Real estate | 28 |  |  | 43 |
Hedge funds | 17 |  |  | 16 |
Total assets measured at net asset value | $ | 285 |  |  | $ | 320 |
___________ (a)Interest -bearing cash is classified as Level 2. (b)Substantially all corporate bonds are rated investment grade by a major ratings agency such as Moody's. (c)Consists primarily of high-yield bonds, emerging market debt, bank loans, securitized bonds and private investment grade fixed income.
Schedule of Fair Value Measurement Inputs and Valuation Techniques | The following tables present the fair value of the Level 3 assets and liabilities by major contract type and the significant unobservable inputs used in the valuations at December 31, 2023 and 2022:
December 31, 2023
|  | Fair Value |  |  |  |  |  |  |  |  |  |
Contract Type (a) |  | Assets |  | Liabilities |  | Total |  | Valuation Technique |  | Significant Unobservable Input |  | Range (b) |  | Average (b)
Electricity purchases and sales |  | $ | 449 |  |  | $ | (1,273) |  |  | $ | (824) |  |  | Income Approach |  | Hourly price curve shape (c) |  | $ | — |  | to | $ | 85 |  |  | $ | 44 |
|  |  |  |  |  |  |  |  | MWh
|  |  |  |  |  |  |  |  |  | Illiquid delivery periods for hub power prices and Heat Rates (d) |  | $ | 30 |  | to | $ | 110 |  |  | $ | 71 |
|  |  |  |  |  |  |  |  |  |  | MWh
Options |  | 1 |  |  | (237) |  |  | (236) |  |  | Option Pricing Model |  | Natural gas to power correlation (e) |  | 10 | % | to | 100 | % |  | 55 | %
|  |  |  |  |  |  |  | Power and natural gas volatility (e) |  | 10 | % | to | 870 | % |  | 441 | %
Financial transmission rights |  | 157 |  |  | (34) |  |  | 123 |  |  | Market Approach (f) |  | Illiquid price differences between settlement points (g) |  | $ | (85) |  | to | $ | 25 |  |  | $ | (30) |
|  |  |  |  |  |  |  |  | MWh
Natural gas |  | 9 |  |  | (112) |  |  | (103) |  |  | Income Approach |  | Natural gas basis (h) |  | $ | — |  | to | $ | 15 |  |  | $ | 6 |
|  |  |  |  |  |  |  |  | MMBtu
|  |  |  |  |  |  |  |  | Illiquid delivery periods (i) |  | $ | — |  | to | $ | 5 |  |  | $ | 4 |
|  |  |  |  |  |  |  |  |  |  |  | MMBtu
Other (j) |  | 14 |  |  | (18) |  |  | (4) |  |  |  |  |  |  |  |  |  |  |
Total |  | $ | 630 |  |  | $ | (1,674) |  |  | $ | (1,044) |  |  |  |  |  |  |  |  |  |  |
December 31, 2022
|  | Fair Value |  |  |  |  |  |  |  |  |  |
Contract Type (a) |  | Assets |  | Liabilities |  | Total |  | Valuation Technique |  | Significant Unobservable Input |  | Range (b) |  | Average (b)
Electricity purchases and sales |  | $ | 603 |  |  | $ | (1,332) |  |  | $ | (729) |  |  | Income Approach |  | Hourly price curve shape (c) |  | $ | — |  | to | $ | 80 |  |  | $ | 38 |
|  |  |  |  |  |  |  |  | MWh |  |
|  |  |  |  |  |  |  |  |  | Illiquid delivery periods for hub power prices and Heat Rates (d) |  | $ | 25 |  | to | $ | 95 |  |  | $ | 60 |
|  |  |  |  |  |  |  |  |  |  | MWh |  |
Options |  | — |  |  | (483) |  |  | (483) |  |  | Option Pricing Model |  | Natural gas to power correlation (e) |  | 10 | % | to | 100 | % |  | 56 | %
|  |  |  |  |  |  |  | Power and natural gas volatility (e) |  | 5 | % | to | 620 | % |  | 313 | %
Financial transmission rights |  | 132 |  |  | (31) |  |  | 101 |  |  | Market Approach (f) |  | Illiquid price differences between settlement points (g) |  | $ | (35) |  | to | $ | 10 |  |  | $ | (11) |
|  |  |  |  |  |  |  |  | MWh |  |
Natural gas |  | 20 |  |  | (155) |  |  | (135) |  |  | Income Approach |  | Natural gas basis (h) |  | $ | — |  | to | $ | 30 |  |  | $ | 13 |
|  |  |  |  |  |  |  |  | MMBtu
Other (j) |  | 36 |  |  | (9) |  |  | 27 |  |  |  |  |  |  |  |  |  |  |
Total |  | $ | 791 |  |  | $ | (2,010) |  |  | $ | (1,219) |  |  |  |  |  |  |  |  |  |  |
____________ (a)Electricity purchase and sales contracts include power and Heat Rate positions in ERCOT, PJM, ISO-NE, NYISO, MISO and CAISO regions. The forward purchase contracts (swaps and options) used to hedge electricity price differences between settlement points are referred to as congestion revenue rights (CRRs) in ERCOT and financial transmission rights (FTRs) in PJM, ISO-NE, NYISO and MISO regions. Natural gas includes swaps and forward contracts. Options consist of physical electricity options, spread options and natural gas options. (b)The range of the inputs may be influenced by factors such as time of day, delivery period, season and location. The average represents the arithmetic average of the underlying inputs and is not weighted by the related fair value or notional amount. (c)Primarily based on the historical range of forward average hourly ERCOT North Hub and ERCOT South and West Zone prices. (d)Primarily based on historical forward ERCOT and PJM power prices and ERCOT Heat Rate variability. (e)Primarily based on the historical forward correlation and volatility within ERCOT and PJM. (f)While we use the market approach, there is insufficient market data to consider the valuation liquid. (g)Primarily based on the historical price differences between settlement points within ERCOT hubs and load zones. (h)Primarily based on the historical forward PJM and Northeast natural gas basis prices and fixed prices. (i)Primarily based on the historical forward natural gas fixed prices. (j)Other includes contracts for coal and environmental allowances.
Schedule of Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation | The following table presents the changes in fair value of the Level 3 assets and liabilities for the years ended December 31, 2023, 2022 and 2021.
| Year Ended December 31,
| 2023 |  | 2022 |  | 2021
Net asset (liability) balance at beginning of period | $ | (1,219) |  |  | $ | (360) |  |  | $ | 22 |
Total unrealized valuation losses | (765) |  |  | (1,382) |  |  | (53) |
Purchases, issuances and settlements (a): |  |  |  |  |
Purchases | 222 |  |  | 185 |  |  | 114 |
Issuances | (30) |  |  | (62) |  |  | (36) |
Settlements | 136 |  |  | 345 |  |  | (314) |
Transfers into Level 3 (b) | (48) |  |  | (30) |  |  | (2) |
Transfers out of Level 3 (b) | 660 |  |  | 85 |  |  | (91) |
Net change (c) | 175 |  |  | (859) |  |  | (382) |
Net (liability) balance at end of period | $ | (1,044) |  |  | $ | (1,219) |  |  | $ | (360) |
Unrealized valuation losses relating to instruments held at end of period | $ | (676) |  |  | $ | (977) |  |  | $ | (364) |
____________ (a)Settlements reflect reversals of unrealized mark-to-market valuations previously recognized in net income. Purchases and issuances reflect option premiums paid or received, including CRRs and FTRs. (b)Includes transfers due to changes in the observability of significant inputs. All Level 3 transfers during the periods presented are in and out of Level 2. For the year ended December 31, 2023, transfers into Level 3 primarily consist of power derivatives where forward pricing inputs have become unobservable and transfers out of Level 3 primarily consist of power and coal derivatives where forward pricing inputs have become observable. For the year ended December 31, 2022, transfers into Level 3 primarily consist of power and coal derivatives where forward pricing inputs have become unobservable and transfers out of Level 3 primarily consist of power, natural gas, and coal derivatives where forward pricing inputs have become observable. (c)Activity excludes change in fair value in the month positions settle. Substantially all changes in values of commodity contracts are reported as operating revenues in our consolidated statements of operations.

X
- Definition Tabular disclosure of input and valuation technique used to measure fair value and change in valuation approach and technique for each separate class of asset and liability measured on recurring and nonrecurring basis. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb) -SubTopic 10 -Topic 820 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_FairValueDisclosuresAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset) using recurring unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -SubTopic 10 -Topic 820 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -SubTopic 10 -Topic 820 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-3 + Details
Name: | us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of assets and liabilities, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 + Details
Name: | us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration