Consolidated Statements of Income (USD $)
In Millions, except Per Share data
3 Months Ended9 Months Ended
Sep. 30, 2011
Sep. 30, 2010
Sep. 30, 2011
Sep. 30, 2010
Operating Revenue$ 1,464$ 1,443$ 4,883$ 4,750
Operating Expenses    
Fuel for electric generation199183504472
Purchased and interchange power365363968955
Purchased power - related parties23216463
Cost of gas sold1071041,0951,060
Maintenance and other operating expenses301273868844
Depreciation and amortization120133404436
General taxes3349151156
Insurance settlement000(50)
Gain on asset sales, net0(2)0(6)
Total operating expenses1,1481,1244,0543,930
Operating Income316319829820
Other Income (Expense)    
Interest income45814
Allowance for equity funds used during construction1144
Income from equity method investees43108
Other income391227
Other expense(3)(2)(8)(7)
Total other income9162646
Interest Charges    
Interest on long-term debt9997298293
Other interest expense661834
Allowance for borrowed funds used during construction(1)(1)(3)(3)
Total interest charges104102313324
Income Before Income Taxes221233542542
Income Tax Expense8187168207
Income from Continuing Operations140146374335
Income (Loss) From Discontinued Operations, Net of Tax002(17)
Net Income140146376318
Income Attributable to Noncontrolling Interests1123
Net Income Attributable to CMS Energy139145374315
Charge for Deferred Issuance Costs on Preferred Stock0808
Preferred Stock Dividends0308
Net Income Available to Common Stockholders139134374299
Net Income Attributable to Common Stockholders    
Amounts Attributable to Continuing Operations139134372316
Amounts Attributable to Discontinued Operations002(17)
Net Income Available to Common Stockholders139134374299
Income Attributable to Noncontrolling Interests    
Amounts Attributable to Continuing Operations1123
Loss from Discontinued Operations0000
Income Attributable to Noncontrolling Interests1123
Basic Earnings Per Average Common Share    
Basic Earnings from Continuing Operations$ 0.55$ 0.58$ 1.48$ 1.38
Basic Earnings (Loss) from Discontinued Operations$ 0.00$ 0.00$ 0.01$ (0.08)
Basic Earnings Attributable to Common Stock$ 0.55$ 0.58$ 1.49$ 1.30
Diluted Earnings Per Average Common Share    
Diluted Earnings from Continuing Operations$ 0.53$ 0.53$ 1.42$ 1.26
Diluted Earnings (Loss) from Discontinued Operations$ 0.00$ 0.00$ 0.01$ (0.07)
Diluted Earnings Attributable to Common Stock$ 0.53$ 0.53$ 1.43$ 1.19
Dividends Declared Per Common Share$ 0.21$ 0.15$ 0.63$ 0.45
Consumers Energy Company [Member]
    
Operating Revenue1,3971,3704,6884,536
Operating Expenses    
Fuel for electric generation175157442407
Purchased and interchange power362359954946
Purchased power - related parties24226463
Cost of gas sold88921,0381,001
Maintenance and other operating expenses286258824801
Depreciation and amortization119131401432
General taxes3847153151
Total operating expenses1,0921,0663,8763,801
Operating Income305304812735
Other Income (Expense)    
Interest income24613
Interest and dividend income - related parties1 1 
Allowance for equity funds used during construction1144
Other income391627
Other expense(3)(2)(8)(7)
Total other income4121937
Interest Charges    
Interest on long-term debt6260188183
Other interest expense551430
Allowance for borrowed funds used during construction(1)(1)(3)(3)
Total interest charges6664199210
Income Before Income Taxes243252632562
Income Tax Expense8892232207
Net Income155160400355
Preferred Stock Dividends1122
Net Income Available to Common Stockholders154159398353
Net Income Attributable to Common Stockholders    
Net Income Available to Common Stockholders$ 154$ 159$ 398$ 353