Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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- Definition

Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Weighted average interest rate of debt outstanding.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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The cash inflow associated with the deconsolidation of a previously consolidated subsidiary or sale of an entity that is related to it but not strictly controlled.

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The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

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Financings and Capitalization (Major Long-Term Debt Issuances and Retirements) (Details) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Jan. 31, 2023	Jun. 30, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Nov. 30, 2022	Sep. 30, 2022	Jul. 31, 2022
Debt Instrument [Line Items]
Principal (In Millions)			$ 1,900
Loans outstanding			14,362	$ 12,568
Repayment of debt			106	235	$ 2,010
NorthStar Clean Energy, Including Subsidiaries
Debt Instrument [Line Items]
Principal (In Millions)			100
Consumers Energy Company
Debt Instrument [Line Items]
Principal (In Millions)			1,800
Loans outstanding			10,277	8,505
Repayment of debt			28	27	$ 1,086
NWO Holdco, L.L.C
Debt Instrument [Line Items]
Sale of noncontrolling interest		$ 49
Term loan facility \| Term Loan Facility Due 2023 \| NorthStar Clean Energy, Including Subsidiaries
Debt Instrument [Line Items]
Principal (In Millions)			$ 100
Interest rate			5.423%
Maximum borrowing capacity			$ 185
Loans outstanding			100	0
Term loan facility \| Term Loan Facility Due 2023 \| Subsequent Event \| NorthStar Clean Energy, Including Subsidiaries
Debt Instrument [Line Items]
Principal (In Millions)	$ 30
Term loan facility \| Term Loan Facility Due January 2024 \| Consumers Energy Company
Debt Instrument [Line Items]
Principal (In Millions)			1,000
Term loan facility \| Unsecured Term Loan Credit Agreement Due January 2024 \| Consumers Energy Company
Debt Instrument [Line Items]
Principal (In Millions)								$ 1,000
Term loan facility \| Unsecured Term Loan Credit Agreement Due January 2024 \| Consumers Energy Company \| Subsequent Event
Debt Instrument [Line Items]
Repayment of debt	500
Term loan facility \| Tranche 1 \| Consumers Energy Company
Debt Instrument [Line Items]
Loans outstanding							$ 550
Term loan facility \| Tranche 2 \| Consumers Energy Company
Debt Instrument [Line Items]
Loans outstanding						$ 450
Term loan facility \| Term Loan Facility Due October 2025
Debt Instrument [Line Items]
Principal (In Millions)			76
First mortgage bonds \| Consumers Energy Company
Debt Instrument [Line Items]
Loans outstanding			8,997	$ 8,197
First mortgage bonds \| First Mortgage Bonds Due August 2032 \| Consumers Energy Company
Debt Instrument [Line Items]
Principal (In Millions)			$ 350
Interest rate			3.60%
First mortgage bonds \| First Mortgage Bonds Due September 2052 \| Consumers Energy Company
Debt Instrument [Line Items]
Principal (In Millions)			$ 450
Interest rate			4.20%
First mortgage bonds \| 5.250% First Mortgage Bonds \| Consumers Energy Company \| Subsequent Event
Debt Instrument [Line Items]
Principal (In Millions)	$ 400
Weighted average interest rate	5.251%
First mortgage bonds \| 4.650% First Mortgage Bonds Due March 2028 \| Consumers Energy Company \| Subsequent Event
Debt Instrument [Line Items]
Principal (In Millions)	$ 425
Interest rate	4.65%