Accounts Receivable - Balance Sheet Supplemental Information (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	$ 4,414	$ 4,266
Allowance for credit losses	157	158
Customer accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	3,960	3,577
Allowance for credit losses	157	158
Other accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	454	689
Allowance for credit losses	0	9
Constellation Energy Generation, LLC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	4,392	4,251
Constellation Energy Generation, LLC \| Customer accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	3,960	3,577
Allowance for credit losses	157	158
Constellation Energy Generation, LLC \| Other accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	432	674
Allowance for credit losses	$ 0	$ 9

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.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 40
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481628/310-20-40-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

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Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

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Amount of allowance for credit loss on accounts receivable, classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(4))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-4

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