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Regulatory Matters (Tables) - Consumers Energy Company [Member] | 12 Months Ended
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Dec. 31, 2015
Public Utility, Property, Plant and Equipment [Line Items] |
Schedule of Regulatory Assets and Liabilities |
In Millions
December 31 | End of Recovery or Refund Period | 2015 | 2014 |
Regulatory assets |  |  |  |  |  |  |  |
Current |  |  |  |  |  |  |  |
Energy optimization plan incentive 1 | 2016 |  | $ | 16 |  | $ | 17 |
Securitized costs – electric utility restructuring legislation 2 | 2015 |  |  | - |  |  | 61 |
Major maintenance 2 | 2015 |  |  | - |  |  | 8 |
Other | 2015 |  |  | - |  |  | 3 |
Total current regulatory assets |  |  | $ | 16 |  | $ | 89 |
Non-current |  |  |  |  |  |  |  |
Postretirement benefits 3 | various |  | $ | 1,096 |  | $ | 1,195 |
Securitized costs – electric generating units to be retired 2 | 2029 |  |  | 348 |  |  | 370 |
ARO 4 | various |  |  | 151 |  |  | 139 |
MGP sites 4 | various |  |  | 146 |  |  | 147 |
Unamortized debt costs 4 | various |  |  | 61 |  |  | 66 |
Gas storage inventory adjustments 4 | various |  |  | 18 |  |  | 21 |
Energy optimization plan incentive 1 | 2017 |  |  | 18 |  |  | 17 |
Other | various |  |  | 2 |  |  | 1 |
Total non‑current regulatory assets |  |  | $ | 1,840 |  | $ | 1,956 |
Total regulatory assets |  |  | $ | 1,856 |  | $ | 2,045 |
Regulatory liabilities |  |  |  |  |  |  |  |
Current |  |  |  |  |  |  |  |
Income taxes, net | 2016 |  | $ | 64 |  | $ | 64 |
Securitized costs – electric utility restructuring legislation | 2016 |  |  | 14 |  |  | - |
Other | 2016 |  |  | 4 |  |  | 3 |
Total current regulatory liabilities |  |  | $ | 82 |  | $ | 67 |
Non-current |  |  |  |  |  |  |  |
Cost of removal | various |  | $ | 1,745 |  | $ | 1,673 |
Renewable energy plan | 2028 |  |  | 109 |  |  | 131 |
ARO | various |  |  | 73 |  |  | 83 |
Income taxes, net | various |  |  | 64 |  |  | 103 |
Renewable energy grant | 2043 |  |  | 60 |  |  | 63 |
Energy optimization plan | various |  |  | 26 |  |  | 32 |
Other | various |  |  | 11 |  |  | 10 |
Total non‑current regulatory liabilities |  |  | $ | 2,088 |  | $ | 2,095 |
Total regulatory liabilities |  |  | $ | 2,170 |  | $ | 2,162 |
| 1 |  | These regulatory assets have arisen from alternative revenue programs and are not associated with incurred costs or capital investments. Therefore, the MPSC has provided for recovery without a return.
| 2 |  | These regulatory assets are included in rate base (or are expected to be included, for costs incurred subsequent to the most recently approved rate case), thereby providing a return on expenditures, or provide a specific return on investment authorized by the MPSC.
| 3 |  | This regulatory asset is offset partially by liabilities. The net amount is included in rate base, thereby providing a return.
| 4 |  | These regulatory assets represent incurred costs for which the MPSC has provided, or Consumers expects, recovery without a return on investment.
Schedule of Assets and Liabilities for PSCR and GCR Underrecoveries and Overrecoveries |
In Millions
December 31 | 2015 | 2014 |
Assets |  |  |  |  |  |  |
Accrued gas revenue |  | $ | - |  | $ | 27 |
Liabilities |  |  |  |  |  |  |
Accrued rate refunds |  |  | 26 |  |  | 6 |

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- Definition The entire disclosure for detailed information about regulatory assets and liabilities, including current and noncurrent assets created when regulatory agencies permit the deferral of costs to the balance sheet that would otherwise be required to appear on the company's income statement and would be charged against current expenses or revenues, as well as current and noncurrent liabilities created when regulatory agencies permit. + References No definition available. + Details
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