Notes Receivable (Schedule Of Current And Non-Current Notes Receivable) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current notes receivable	$ 96	$ 63
Total notes receivable	848	698
Consumers Energy Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current notes receivable		14
Total notes receivable		14
EnerBank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current notes receivable	95	48
Noncurrent notes receivable	752	635
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current notes receivable	1	15
Other [Member] | Consumers Energy Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current notes receivable		$ 14