Contingencies and Commitments (Schedule of Contractual Purchase Obligations) (Details) $ in Millions	Dec. 31, 2024 USD ($)
Guarantees And Other Contingencies [Line Items]
Total	$ 11,438
2025	2,439
2026	1,757
2027	1,368
2028	1,138
2029	917
Beyond 2029	3,819
Consumers Energy Company
Guarantees And Other Contingencies [Line Items]
Total	10,377
2025	2,071
2026	1,620
2027	1,216
2028	1,042
2029	794
Beyond 2029	3,634
Total PPAs \| Consumers Energy Company
Guarantees And Other Contingencies [Line Items]
Total	7,006
2025	659
2026	662
2027	698
2028	677
2029	678
Beyond 2029	3,632
Other
Guarantees And Other Contingencies [Line Items]
Total	4,432
2025	1,780
2026	1,095
2027	670
2028	461
2029	239
Beyond 2029	187
Other \| Consumers Energy Company
Guarantees And Other Contingencies [Line Items]
Total	3,371
2025	1,412
2026	958
2027	518
2028	365
2029	116
Beyond 2029	2
MCV PPA \| Consumers Energy Company
Guarantees And Other Contingencies [Line Items]
Total	1,297
2025	265
2026	233
2027	218
2028	222
2029	239
Beyond 2029	120
Related-party PPAs \| Consumers Energy Company
Guarantees And Other Contingencies [Line Items]
Total	60
2025	29
2026	15
2027	16
2028	0
2029	0
Beyond 2029	0
Other PPAs \| Consumers Energy Company
Guarantees And Other Contingencies [Line Items]
Total	5,649
2025	365
2026	414
2027	464
2028	455
2029	439
Beyond 2029	$ 3,512

Guarantees And Other Contingencies [Line Items]

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Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Includes, but is not limited to, lease not yet commenced.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 440
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482648/440-10-50-4

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-3

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Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Includes, but is not limited to, lease not yet commenced.

+ References

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Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Includes, but is not limited to, lease not yet commenced.

+ References

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+ References

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+ References

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Amount of unrecorded obligation to transfer funds in future for fixed or minimum amount or quantity of product and service at fixed or minimum price. Includes, but is not limited to, lease not yet commenced and take-or-pay and throughput contracts.

+ References

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Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Includes, but is not limited to, lease not yet commenced.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 440
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482648/440-10-50-4

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-3

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