v3.25.2
Reportable Segments (Schedule of Financial Information by Reportable Segments, CMS Energy, including Consumers) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Segment Reporting Information [Line Items]          
Operating Revenue $ 1,838 $ 1,607 $ 4,285 $ 3,783  
Power supply cost 603 479 1,218 967  
Maintenance and other operating expenses 397 404 802 806  
Depreciation and amortization 288 273 676 641  
General taxes 109 102 271 257  
Total operating expenses 1,521 1,324 3,474 3,088  
Operating Income 317 283 811 695  
Total other income 137 113 187 199  
Total interest charges 199 173 385 350  
Income (Loss) Before Income Taxes 255 223 613 544  
Income tax expense (benefit) 62 41 125 99  
Income (Loss) From Continuing Operations 193 182 488 445  
Other segment items 5 13 12 35  
Net Income (Loss) Available to Common Stockholders 198 195 500 480  
Plant, property, and equipment, gross 35,962 33,680 35,962 33,680 $ 34,932
Total assets 37,699 34,355 37,699 34,355 $ 35,920
Cost of gas sold          
Segment Reporting Information [Line Items]          
Cost of gas sold 124 66 507 417  
Operating Segments          
Segment Reporting Information [Line Items]          
Operating Revenue 1,838 1,607 4,285 3,783  
Power supply cost 603 479 1,218 967  
Maintenance and other operating expenses 394 401 797 801  
Depreciation and amortization 288 273 676 640  
General taxes 109 102 271 257  
Total operating expenses 1,518 1,321 3,469 3,082  
Operating Income 320 286 816 701  
Total other income 61 61 108 123  
Total interest charges 139 125 269 255  
Income (Loss) Before Income Taxes 242 222 655 569  
Income tax expense (benefit) 36 37 139 111  
Income (Loss) From Continuing Operations 206 185 516 458  
Other segment items 8 16 17 40  
Net Income (Loss) Available to Common Stockholders 214 201 533 498  
Plant, property, and equipment, gross 35,932 33,659 35,932 33,659  
Total assets 37,435 34,250 37,435 34,250  
Operating Segments | Cost of gas sold          
Segment Reporting Information [Line Items]          
Cost of gas sold 124 66 507 417  
Other Reconciling Items          
Segment Reporting Information [Line Items]          
Operating Revenue 0 0 0 0  
Power supply cost 0 0 0 0  
Maintenance and other operating expenses 3 3 5 5  
Depreciation and amortization 0 0 0 1  
General taxes 0 0 0 0  
Total operating expenses 3 3 5 6  
Operating Income (3) (3) (5) (6)  
Total other income 76 52 79 76  
Total interest charges 60 48 116 95  
Income (Loss) Before Income Taxes 13 1 (42) (25)  
Income tax expense (benefit) 26 4 (14) (12)  
Income (Loss) From Continuing Operations (13) (3) (28) (13)  
Other segment items (3) (3) (5) (5)  
Net Income (Loss) Available to Common Stockholders (16) (6) (33) (18)  
Plant, property, and equipment, gross 30 21 30 21  
Total assets 264 105 264 105  
Other Reconciling Items | Cost of gas sold          
Segment Reporting Information [Line Items]          
Cost of gas sold 0 0 0 0  
Electric Utility | Operating Segments          
Segment Reporting Information [Line Items]          
Operating Revenue 1,359 1,226 2,658 2,358  
Power supply cost 537 444 1,083 893  
Maintenance and other operating expenses 264 261 521 499  
Depreciation and amortization 222 209 443 422  
General taxes 73 68 146 139  
Total operating expenses 1,096 982 2,193 1,953  
Operating Income 263 244 465 405  
Total other income 36 36 63 70  
Total interest charges 89 79 171 160  
Income (Loss) Before Income Taxes 210 201 357 315  
Income tax expense (benefit) 42 30 65 47  
Income (Loss) From Continuing Operations 168 171 292 268  
Other segment items (1) (1) (1) (1)  
Net Income (Loss) Available to Common Stockholders 167 170 291 267  
Plant, property, and equipment, gross 20,761 19,557 20,761 19,557  
Total assets 21,942 20,122 21,942 20,122  
Electric Utility | Operating Segments | Cost of gas sold          
Segment Reporting Information [Line Items]          
Cost of gas sold 0 0 0 0  
Gas Utility | Operating Segments          
Segment Reporting Information [Line Items]          
Operating Revenue 387 307 1,436 1,272  
Power supply cost 0 0 0 0  
Maintenance and other operating expenses 112 116 228 256  
Depreciation and amortization 54 51 208 194  
General taxes 33 31 119 112  
Total operating expenses 322 264 1,060 978  
Operating Income 65 43 376 294  
Total other income 23 23 42 45  
Total interest charges 51 46 99 94  
Income (Loss) Before Income Taxes 37 20 319 245  
Income tax expense (benefit) 12 5 81 61  
Income (Loss) From Continuing Operations 25 15 238 184  
Other segment items 0 0 0 0  
Net Income (Loss) Available to Common Stockholders 25 15 238 184  
Plant, property, and equipment, gross 13,609 12,638 13,609 12,638  
Total assets 13,388 12,469 13,388 12,469  
Gas Utility | Operating Segments | Cost of gas sold          
Segment Reporting Information [Line Items]          
Cost of gas sold 123 66 505 416  
NorthStar Clean Energy | Operating Segments          
Segment Reporting Information [Line Items]          
Operating Revenue 92 74 191 153  
Power supply cost 66 35 135 74  
Maintenance and other operating expenses 18 24 48 46  
Depreciation and amortization 12 13 25 24  
General taxes 3 3 6 6  
Total operating expenses 100 75 216 151  
Operating Income (8) (1) (25) 2  
Total other income 2 2 3 8  
Total interest charges (1) 0 (1) 1  
Income (Loss) Before Income Taxes (5) 1 (21) 9  
Income tax expense (benefit) (18) 2 (7) 3  
Income (Loss) From Continuing Operations 13 (1) (14) 6  
Other segment items 9 17 18 41  
Net Income (Loss) Available to Common Stockholders 22 16 4 47  
Plant, property, and equipment, gross 1,562 1,464 1,562 1,464  
Total assets 2,105 1,659 2,105 1,659  
NorthStar Clean Energy | Operating Segments | Cost of gas sold          
Segment Reporting Information [Line Items]          
Cost of gas sold $ 1 $ 0 $ 2 $ 1