Cover Page - shares	6 Months Ended
	Jun. 30, 2020	Jul. 07, 2020
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2020
Document Transition Report	false
Commission File Number	1-9513
Entity Registrant Name	CMS ENERGY CORPORATION
IRS Employer Identification No.	38-2726431
Entity Incorporation State	MI
Entity Address	One Energy Plaza
City	Jackson
State	MI
Postal Zip Code	49201
City Area Code	517
Local Phone Number	788‑0550
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Smaller reporting company	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		286,280,694
Entity Central Index Key	0000811156
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false
Consumers Energy Company
Document Information [Line Items]
Commission File Number	1-5611
Entity Registrant Name	CONSUMERS ENERGY COMPANY
IRS Employer Identification No.	38-0442310
Entity Incorporation State	MI
Entity Address	One Energy Plaza
City	Jackson
State	MI
Postal Zip Code	49201
City Area Code	517
Local Phone Number	788‑0550
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Smaller reporting company	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		84,108,789
Entity Central Index Key	0000201533
Common Stock
Document Information [Line Items]
Title of each class	CMS Energy Corporation Common Stock, $0.01 par value
Trading Symbol	CMS
Security Exchange Name	NYSE
CMS Energy Corporation 5.625% Junior Subordinated Notes due 2078
Document Information [Line Items]
Title of each class	CMS Energy Corporation 5.625% Junior Subordinated Notes due 2078
Trading Symbol	CMSA
Security Exchange Name	NYSE
CMS Energy Corporation 5.875% Junior Subordinated Notes due 2078
Document Information [Line Items]
Title of each class	CMS Energy Corporation 5.875% Junior Subordinated Notes due 2078
Trading Symbol	CMSC
Security Exchange Name	NYSE
CMS Energy Corporation 5.875% Junior Subordinated Notes due 2079
Document Information [Line Items]
Title of each class	CMS Energy Corporation 5.875% Junior Subordinated Notes due 2079
Trading Symbol	CMSD
Security Exchange Name	NYSE
Consumers Energy Company Cumulative Preferred Stock, $100 par value: $4.50 Series
Document Information [Line Items]
Title of each class	Consumers Energy Company Cumulative Preferred Stock, $100 par value: $4.50 Series
Trading Symbol	CMS-PB
Security Exchange Name	NYSE