Notes Receivable (Schedule Of Current And Non-Current Notes Receivable) (Details) - USD ($)
$ in Millions |
Sep. 30, 2016 |
Dec. 31, 2015 |
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Current notes receivable |
$ 146
|
$ 128
|
| EnerBank notes receivable held for sale |
41
|
16
|
| Total notes receivable |
1,286
|
1,161
|
| Consumers Energy Company [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Total notes receivable |
45
|
|
| EnerBank [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Noncurrent notes receivable |
1,051
|
1,017
|
| Receivables, Net Of Allowance For Loan Losses [Member] | EnerBank [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Current notes receivable |
146
|
128
|
| Receivables Held For Sale [Member] | EnerBank [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| EnerBank notes receivable held for sale |
41
|
$ 16
|
| State Of Michigan Tax Settlement [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Noncurrent notes receivable |
48
|
|
| State Of Michigan Tax Settlement [Member] | Consumers Energy Company [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Noncurrent notes receivable |
$ 45
|
|