Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

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Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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Notes Receivable (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018	Jul. 31, 2018
EnerBank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable	$ 2,018	$ 1,857
Unearned income	111	102
Delinquent loans	20	21
Loans modified as troubled debt restructurings	1	1
Consumers Energy Company
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable	105	106
Current portion notes receivable related party	7	$ 7
Retail Installment Contracts \| EnerBank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable	131
Interest Rate Swap Notes Receivable \| EnerBank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest rate swap	$ 36
CMS Energy Note Payable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest Rate			4.10%