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Fair Value of Financial Assets and Liabilities - Fair Value Measurement of Assets and Liabilities, Recurring (Details) - USD ($) $ in Millions | Mar. 31, 2025 | Dec. 31, 2024
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Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis [Abstract] |  |
Derivative asset notational amounts | $ 1,254 | $ 1,119
Cash and Cash Equivalents | Constellation Energy Generation, LLC |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 1,817 | 2,924
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 1,817 | 2,924
Cash and Cash Equivalents | CEG Parent |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 38 | 130
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 38 | 130
Restricted cash | Constellation Energy Generation, LLC |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 77 | 71
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 77 | 71
Cash | CEG Parent |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 10 | 4
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 10 | 4
NDT fund investments subtotal |  |
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis [Abstract] |  |
Net liabilities | 162 | 148
Fair Value, Recurring |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 28 | 120
Deferred compensation obligation | (89) | (93)
Total liabilities measured at fair value | (997) | (959)
Total net assets | 18,083 | 18,186
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 28 | 120
Fair Value, Recurring | Mark-to-market derivative liabilities subtotal |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative liabilities | (908) | (866)
Fair Value, Recurring | Economic hedges |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative liabilities | (13,366) | (9,462)
Fair Value, Recurring | Effect of netting and allocation of collateral |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative liabilities | 12,458 | 8,596
Fair Value, Recurring | NDT fund investments subtotal |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 17,512 | 17,321
Fair Value, Recurring | Cash equivalents |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 395 | 350
Fair Value, Recurring | Equities NDT |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 7,004 | 7,127
Fair Value, Recurring | Fixed income |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 3,998 | 3,919
Fair Value, Recurring | Private credit |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 128 | 134
Fair Value, Recurring | Rabbi trust investments |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 99 | 100
Fair Value, Recurring | Investments in equities |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 98 | 389
Fair Value, Recurring | Mark-to-market derivative assets subtotal |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative assets | 1,343 | 1,215
Fair Value, Recurring | Economic hedges |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative assets | 12,738 | 9,225
Fair Value, Recurring | Effect of netting and allocation of collateral |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative assets | (11,395) | (8,010)
Total assets measured at fair value | Fair Value, Recurring |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Total assets | 19,080 | 19,145
Level 1 | Fair Value, Recurring |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 28 | 120
Total assets | 8,225 | 8,254
Deferred compensation obligation | 0 | 0
Total liabilities measured at fair value | (72) | (42)
Total net assets | 8,153 | 8,212
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 28 | 120
Level 1 | Fair Value, Recurring | Mark-to-market derivative liabilities subtotal |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative liabilities | (72) | (42)
Level 1 | Fair Value, Recurring | Economic hedges |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative liabilities | (1,947) | (1,222)
Level 1 | Fair Value, Recurring | Effect of netting and allocation of collateral |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative liabilities | 1,875 | 1,180
Level 1 | Fair Value, Recurring | NDT fund investments subtotal |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 7,689 | 7,506
Level 1 | Fair Value, Recurring | Cash equivalents |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 227 | 187
Level 1 | Fair Value, Recurring | Equities NDT |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 5,351 | 5,230
Level 1 | Fair Value, Recurring | Fixed income |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 2,111 | 2,089
Level 1 | Fair Value, Recurring | Private credit |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 0 | 0
Level 1 | Fair Value, Recurring | Rabbi trust investments |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 58 | 58
Level 1 | Fair Value, Recurring | Investments in equities |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 98 | 389
Level 1 | Fair Value, Recurring | Mark-to-market derivative assets subtotal |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative assets | 352 | 181
Level 1 | Fair Value, Recurring | Economic hedges |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative assets | 1,986 | 1,278
Level 1 | Fair Value, Recurring | Effect of netting and allocation of collateral |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative assets | (1,634) | (1,097)
Level 2 | Fair Value, Recurring |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 0 | 0
Total assets | 3,856 | 4,079
Deferred compensation obligation | (89) | (93)
Total liabilities measured at fair value | (398) | (398)
Total net assets | 3,458 | 3,681
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 0 | 0
Level 2 | Fair Value, Recurring | Mark-to-market derivative liabilities subtotal |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative liabilities | (309) | (305)
Level 2 | Fair Value, Recurring | Economic hedges |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative liabilities | (7,939) | (5,462)
Level 2 | Fair Value, Recurring | Effect of netting and allocation of collateral |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative liabilities | 7,630 | 5,157
Level 2 | Fair Value, Recurring | NDT fund investments subtotal |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 3,334 | 3,522
Level 2 | Fair Value, Recurring | Cash equivalents |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 168 | 163
Level 2 | Fair Value, Recurring | Equities NDT |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 1,652 | 1,897
Level 2 | Fair Value, Recurring | Fixed income |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 1,514 | 1,462
Level 2 | Fair Value, Recurring | Private credit |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 0 | 0
Level 2 | Fair Value, Recurring | Rabbi trust investments |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 40 | 41
Level 2 | Fair Value, Recurring | Investments in equities |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 0 | 0
Level 2 | Fair Value, Recurring | Mark-to-market derivative assets subtotal |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative assets | 482 | 516
Level 2 | Fair Value, Recurring | Economic hedges |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative assets | 7,493 | 5,306
Level 2 | Fair Value, Recurring | Effect of netting and allocation of collateral |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative assets | (7,011) | (4,790)
Level 3 | Fair Value, Recurring |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 0 | 0
Total assets | 1,012 | 1,021
Deferred compensation obligation | 0 | 0
Total liabilities measured at fair value | (527) | (519)
Total net assets | 485 | 502
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis [Abstract] |  |
Cash equivalents, fair value disclosure | 0 | 0
Level 3 | Fair Value, Recurring | Mark-to-market derivative liabilities subtotal |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative liabilities | (527) | (519)
Level 3 | Fair Value, Recurring | Economic hedges |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative liabilities | (3,480) | (2,778)
Level 3 | Fair Value, Recurring | Effect of netting and allocation of collateral |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative liabilities | 2,953 | 2,259
Level 3 | Fair Value, Recurring | NDT fund investments subtotal |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 502 | 502
Level 3 | Fair Value, Recurring | Cash equivalents |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 0 | 0
Level 3 | Fair Value, Recurring | Equities NDT |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 1 | 0
Level 3 | Fair Value, Recurring | Fixed income |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 373 | 368
Level 3 | Fair Value, Recurring | Private credit |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 128 | 134
Level 3 | Fair Value, Recurring | Rabbi trust investments |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 1 | 1
Level 3 | Fair Value, Recurring | Investments in equities |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Investments, fair value disclosure | 0 | 0
Level 3 | Fair Value, Recurring | Mark-to-market derivative assets subtotal |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative assets | 509 | 518
Level 3 | Fair Value, Recurring | Economic hedges |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative assets | 3,259 | 2,641
Level 3 | Fair Value, Recurring | Effect of netting and allocation of collateral |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Mark-to-market derivative assets | (2,750) | (2,123)
Assets measured at NAV | Fair Value, Recurring |  |
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] |  |
Total assets | $ 5,987 | $ 5,791

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- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -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 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -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 + Details
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- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. 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