v3.25.4
Financings and Capitalization (Major Long-Term Debt Issuances and Retirements) (Details)
$ in Millions
12 Months Ended
Dec. 31, 2025
USD ($)
Debt Instrument [Line Items]  
Principal Debt Issuances (In Millions) $ 3,458
Repayments of debt 850
Consumers Energy Company  
Debt Instrument [Line Items]  
Principal Debt Issuances (In Millions) 1,125
First mortgage bonds | 4.500% First Mortgage Bonds Due January 2031 | Consumers Energy Company  
Debt Instrument [Line Items]  
Principal Debt Issuances (In Millions) $ 500
Interest Rate (%) 4.50%
First mortgage bonds | 5.050% First Mortgage Bonds Due May 2035 | Consumers Energy Company  
Debt Instrument [Line Items]  
Principal Debt Issuances (In Millions) $ 625
Interest Rate (%) 5.05%
CMS Energy  
Debt Instrument [Line Items]  
Principal Debt Issuances (In Millions) $ 2,110
Repayments of debt 850
CMS Energy | Junior subordinated notes | 6.500% Junior Subordinated Notes Due June 2055  
Debt Instrument [Line Items]  
Principal Debt Issuances (In Millions) $ 1,000
Interest Rate (%) 6.50%
CMS Energy | Term loan facility | Term Loan Facility Due December 2025  
Debt Instrument [Line Items]  
Principal Debt Issuances (In Millions) $ 110
Repayments of debt 200
CMS Energy | Term loan facility | Term Loan Facility Due September 2025  
Debt Instrument [Line Items]  
Repayments of debt 400
CMS Energy | Convertible debt | 3.125% Convertible Notes Due May 2031  
Debt Instrument [Line Items]  
Principal Debt Issuances (In Millions) $ 1,000
Interest Rate (%) 3.125%
CMS Energy | Senior Notes | 3.600% Senior Notes Due November 2025  
Debt Instrument [Line Items]  
Interest Rate (%) 3.60%
Repayments of debt $ 250
NorthStar Clean Energy, Including Subsidiaries  
Debt Instrument [Line Items]  
Principal Debt Issuances (In Millions) 223
NorthStar Clean Energy, Including Subsidiaries | Construction financing agreement | Construction Financing Agreement  
Debt Instrument [Line Items]  
Principal Debt Issuances (In Millions) $ 223