Line of Credit Facility, Extended Term Period

No definition available.

Name:	ceg_LineOfCreditFacilityExtendedTermPeriod
Namespace Prefix:	ceg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Existing Uncommitted Bilateral Facilities

+ References

No definition available.

+ Details

Name:	ceg_NumberOfExistingUncommittedBilateralFacilities
Namespace Prefix:	ceg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 605
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477548/944-605-55-15

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 605
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477548/944-605-55-12

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-SubTopic 10
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The maximum amount of borrowing capacity under a line of credit that is available as of the balance sheet date for financing purchases of goods acquired for inventory or imminent delivery to a customer.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCapacityAvailableForTradePurchases
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of increase (decrease) of the credit facility.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(f))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

+ Details

Name:	us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481544/470-10-50-6

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ShortTermDebtLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=ceg_BilateralCreditAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=ceg_AccountsReceivableFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=ceg_CDHIRevolverMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=ceg_LiquidityFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ceg_CollateralPostedAxis=ceg_NoAdditionalCollateralPostedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=ceg_OtherCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=ceg_AdditionalThirdUncommittedBilateralFacilityMember
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Period Type:

Debt and Credit Agreements - Summary of Bank Commitments, Credit Facility Borrowings and Available Capacity (Details) $ in Millions	1 Months Ended
	Mar. 31, 2026 USD ($)	Feb. 28, 2026 USD ($) facility	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)
Short-term Debt [Line Items]
Aggregate Bank Commitment	$ 15,050		$ 9,458
Facility Draws	1,853		0
Outstanding Letters of Credit	4,544		2,085
Outstanding Commercial Paper	1,957		0
Total Available Capacity	6,682		7,361
Revolving Credit Facility
Short-term Debt [Line Items]
Aggregate Bank Commitment	7,000		4,500
Facility Draws	0		0
Outstanding Letters of Credit	701		40
Outstanding Commercial Paper	1,957		0
Total Available Capacity	$ 4,342		4,460
Weighted average interest rate	3.98%
Bilaterals
Short-term Debt [Line Items]
Aggregate Bank Commitment	$ 4,100	$ 400	2,350
Facility Draws	0		0
Outstanding Letters of Credit	2,632		1,276
Outstanding Commercial Paper	0		0
Total Available Capacity	$ 1,468		1,074
Increase in facility		$ 100
Number of existing uncommitted bilateral facilities \| facility		2
Extended period term	2 years
Bilaterals \| Unsecured Debt
Short-term Debt [Line Items]
Aggregate Bank Commitment		$ 75
Increase in facility	$ 300
Accounts Receivable Facility
Short-term Debt [Line Items]
Aggregate Bank Commitment	1,500		1,500	$ 1,500
Facility Draws	1,500		0
Outstanding Letters of Credit	0		0
Outstanding Commercial Paper	0		0
Total Available Capacity	0		1,500
CDHI Revolver
Short-term Debt [Line Items]
Aggregate Bank Commitment	908
Facility Draws	309
Outstanding Letters of Credit	0
Outstanding Commercial Paper	0
Total Available Capacity	599
Liquidity Facility
Short-term Debt [Line Items]
Aggregate Bank Commitment	971		971
Facility Draws	0		0
Outstanding Letters of Credit	758		647
Outstanding Commercial Paper	0		0
Total Available Capacity	199		312
Liquidity Facility \| No Additional Collateral Posted
Short-term Debt [Line Items]
Outstanding Commercial Paper	957		959
Project Finance
Short-term Debt [Line Items]
Aggregate Bank Commitment	571		137
Facility Draws	44		0
Outstanding Letters of Credit	453		122
Outstanding Commercial Paper	0		0
Total Available Capacity	74		15
Other Credit Facility
Short-term Debt [Line Items]
Facility Draws	$ 15		$ 15
Additional Third Uncommitted Bilateral Facility
Short-term Debt [Line Items]
Increase in facility		$ 200