v3.26.1
Revenue (Schedule of Disaggregation of Revenue) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers $ 1,808 $ 1,798 $ 4,483 $ 4,196
Leasing income 14 34 64 76
Financing income 5 4 9 9
Total operating revenue 1,829 1,838 4,559 4,285
Other        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 89 58 157 115
Consumers Energy Company        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 1,719 1,740 4,326 4,081
Financing income 5 4 9 9
Alternative-revenue programs 2 2 3 4
Total operating revenue 1,726 1,746 4,338 4,094
Consumers Energy Company | Residential        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 908 895 2,461 2,220
Consumers Energy Company | Commercial        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 548 563 1,271 1,220
Consumers Energy Company | Industrial        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 195 209 430 412
Consumers Energy Company | Other        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 68 73 164 229
Operating Segments        
Disaggregation of Revenue [Line Items]        
Total operating revenue 1,829 1,838 4,559 4,285
Operating Segments | Consumers Energy Company        
Disaggregation of Revenue [Line Items]        
Total operating revenue 1,726 1,746 4,338 4,094
Operating Segments | Electric Utility        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 1,333 1,355 2,698 2,649
Financing income 3 2 5 5
Total operating revenue 1,338 1,359 2,706 2,658
Operating Segments | Electric Utility | Consumers Energy Company        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 1,333 1,355 2,698 2,649
Financing income 3 2 5 5
Alternative-revenue programs 2 2 3 4
Total operating revenue 1,338 1,359 2,706 2,658
Operating Segments | Electric Utility | Consumers Energy Company | Residential        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 629 619 1,292 1,213
Operating Segments | Electric Utility | Consumers Energy Company | Commercial        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 467 473 915 891
Operating Segments | Electric Utility | Consumers Energy Company | Industrial        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 188 199 390 372
Operating Segments | Electric Utility | Consumers Energy Company | Other        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 49 64 101 173
Operating Segments | Gas Utility        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 386 385 1,628 1,432
Financing income 2 2 4 4
Total operating revenue 388 387 1,632 1,436
Operating Segments | Gas Utility | Consumers Energy Company        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 386 385 1,628 1,432
Financing income 2 2 4 4
Alternative-revenue programs 0 0 0 0
Total operating revenue 388 387 1,632 1,436
Operating Segments | Gas Utility | Consumers Energy Company | Residential        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 279 276 1,169 1,007
Operating Segments | Gas Utility | Consumers Energy Company | Commercial        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 81 90 356 329
Operating Segments | Gas Utility | Consumers Energy Company | Industrial        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 7 10 40 40
Operating Segments | Gas Utility | Consumers Energy Company | Other        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 19 9 63 56
Operating Segments | NorthStar Clean Energy        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers 89 58 157 115
Leasing income 14 34 64 76
Total operating revenue 103 92 221 191
Variable lease income 9 23 46 54
Operating Segments | NorthStar Clean Energy | Other        
Disaggregation of Revenue [Line Items]        
Revenue recognized from contracts with customers $ 89 $ 58 $ 157 $ 115