Consumers Energy Company Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Net gain (loss) arising during the period, tax	$ 1	$ 2	$ 0
Amortization of net actuarial loss, tax	0	0	1
Consumers Energy Company
Net gain (loss) arising during the period, tax	1	0	5
Amortization of net actuarial loss, tax	$ 0	$ 0	$ 0

Amount of tax expense (benefit) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 12
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-12

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration