Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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- Definition

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.

+ References

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- Definition

The average effective interest rate during the reporting period.

+ References

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-Publisher FASB
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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

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

+ References

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- Definition

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.

+ References

No definition available.

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- Definition

Description of the maturity date of the debt instrument including whether the debt matures serially and, if so, a brief description of the serial maturities.

+ References

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- Definition

Amount, after accumulated amortization, of debt discount (premium).

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- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

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- Definition

Amount of interest-bearing domestic third-party deposits placed by or through the assistance of a deposit broker, also known as brokered deposit liabilities.

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- Definition

Nominal or face amount on the investment owned.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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- Definition

Weighted average interest rate of long-term debt outstanding calculated at point in time.

+ References

No definition available.

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- Definition

The weighted average interest rate for domestic brokered deposit liabilities.

+ References

No definition available.

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Financings and Capitalization (Summary of Long-Term Debt Outstanding) (Details) - USD ($)	1 Months Ended	12 Months Ended
	Oct. 31, 2022	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Principal amounts outstanding		$ 11,683,000,000	$ 10,265,000,000
Current amounts		(974,000,000)	(1,081,000,000)
Net unamortized discounts		(21,000,000)	(14,000,000)
Unamortized issuance costs		(73,000,000)	(47,000,000)
Long-term debt		10,615,000,000	9,123,000,000
Consumers Energy Company
Debt Instrument [Line Items]
Principal amounts outstanding		6,862,000,000	5,940,000,000
Current amounts		(26,000,000)	(343,000,000)
Net unamortized discounts		(16,000,000)	(8,000,000)
Unamortized issuance costs		(41,000,000)	(28,000,000)
Long-term debt		$ 6,779,000,000	5,561,000,000
FMB's 5.650% Due 2018 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		5.65%
FMB's 6.125% Due 2019 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		6.125%
FMB's 6.700% Due 2019 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		6.70%
Tax-exempt pollution control revenue bond \| Consumers Energy Company
Debt Instrument [Line Items]
Maturity Date		2035
Principal amounts outstanding		$ 35,000,000	103,000,000
Term loans and revolving credit agreements
Debt Instrument [Line Items]
Maturity Date		2025
Principal amounts outstanding		$ 98,000,000	0
Three-month LIBOR plus a spread		1.50%
Interest rate at period end		4.303%
Fixed interest rate		4.702%
Certificates of deposit \| EnerBank Certificates Of Deposit
Debt Instrument [Line Items]
Maturity Date		2019-2026
Certificates of deposit		$ 1,758,000,000	$ 1,245,000,000
Weighted-average interest rate		2.44%	1.758%
Certificate of deposit face value		$ 1,000
First Mortgage Bonds \| Consumers Energy Company
Debt Instrument [Line Items]
Principal amounts outstanding		$ 6,335,000,000	$ 5,535,000,000
First Mortgage Bonds \| FMB's 5.650% Due 2018 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		5.65%
Maturity Date		2018
Principal amounts outstanding		$ 0	250,000,000
First Mortgage Bonds \| FMB's 6.125% Due 2019 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		6.125%
Maturity Date		2019
Principal amounts outstanding		$ 0	350,000,000
First Mortgage Bonds \| FMB's 6.700% Due 2019 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		6.70%
Maturity Date		2019
Principal amounts outstanding		$ 0	500,000,000
First Mortgage Bonds \| FMB's 5.650% Due 2020 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		5.65%
Maturity Date		2020
Principal amounts outstanding		$ 300,000,000	300,000,000
First Mortgage Bonds \| FMB's 3.770% Due 2020 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		3.77%
Maturity Date		2020
Principal amounts outstanding		$ 100,000,000	100,000,000
First Mortgage Bonds \| FMB's 2.850% Due 2022 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		2.85%
Maturity Date		2022
Principal amounts outstanding		$ 375,000,000	375,000,000
First Mortgage Bonds \| FMB's 5.300% Due 2022 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		5.30%
Maturity Date		2022
Principal amounts outstanding		$ 250,000,000	250,000,000
First Mortgage Bonds \| FMB's 3.375% Due 2023 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		3.375%
Maturity Date		2023
Principal amounts outstanding		$ 325,000,000	325,000,000
First Mortgage Bonds \| FMB's 3.125% Due 2024 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		3.125%
Maturity Date		2024
Principal amounts outstanding		$ 250,000,000	250,000,000
First Mortgage Bonds \| FMB's 3.190% Due 2024 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		3.19%
Maturity Date		2024
Principal amounts outstanding		$ 52,000,000	52,000,000
First Mortgage Bonds \| FMB's 3.680% Due 2027 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		3.68%
Maturity Date		2027
Principal amounts outstanding		$ 100,000,000	0
First Mortgage Bonds \| FMB's 3.390% Due 2027 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		3.39%
Maturity Date		2027
Principal amounts outstanding		$ 35,000,000	35,000,000
First Mortgage Bonds \| FMB's 3.800% Due 2028 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		3.80%
Maturity Date		2028
Principal amounts outstanding		$ 300,000,000	0
First Mortgage Bonds \| FMB's 3.180% Due 2032 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		3.18%
Maturity Date		2032
Principal amounts outstanding		$ 100,000,000	100,000,000
First Mortgage Bonds \| FMB's 5.800% Due 2035 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		5.80%
Maturity Date		2035
Principal amounts outstanding		$ 175,000,000	175,000,000
First Mortgage Bonds \| FMB's 3.520% Due 2037 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		3.52%
Maturity Date		2037
Principal amounts outstanding		$ 335,000,000	335,000,000
First Mortgage Bonds \| FMB's 4.010% Due 2038 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		4.01%
Maturity Date		2038
Principal amounts outstanding		$ 215,000,000	0
First Mortgage Bonds \| FMB's 6.170% Due 2040 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		6.17%
Maturity Date		2040
Principal amounts outstanding		$ 50,000,000	50,000,000
First Mortgage Bonds \| FMB's 4.970% Due 2040 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		4.97%
Maturity Date		2040
Principal amounts outstanding		$ 50,000,000	50,000,000
First Mortgage Bonds \| FMB's 4.310% Due 2042 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		4.31%
Maturity Date		2042
Principal amounts outstanding		$ 263,000,000	263,000,000
First Mortgage Bonds \| FMB's 3.950% Due 2043 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		3.95%
Maturity Date		2043
Principal amounts outstanding		$ 425,000,000	425,000,000
First Mortgage Bonds \| FMB's 4.100% Due 2045 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		4.10%
Maturity Date		2045
Principal amounts outstanding		$ 250,000,000	250,000,000
First Mortgage Bonds \| FMB's 3.250% Due 2046 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		3.25%
Maturity Date		2046
Principal amounts outstanding		$ 450,000,000	450,000,000
First Mortgage Bonds \| FMB's 3.950% Due 2047 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		3.95%
Maturity Date		2047
Principal amounts outstanding		$ 350,000,000	350,000,000
First Mortgage Bonds \| FMB's 4.350% Due 2049 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		4.35%
Maturity Date		2049
Principal amounts outstanding		$ 550,000,000	0
First Mortgage Bonds \| FMB's 4.050% Due 2048 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		4.05%
Maturity Date		2048
Principal amounts outstanding		$ 550,000,000	0
First Mortgage Bonds \| FMB's 3.860% Due 2052 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		3.86%
Maturity Date		2052
Principal amounts outstanding		$ 50,000,000	50,000,000
First Mortgage Bonds \| FMB's 4.280% Due 2057 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		4.28%
Maturity Date		2057
Principal amounts outstanding		$ 185,000,000	0
First Mortgage Bonds \| FMB's 4.350% Due 2064 \| Consumers Energy Company
Debt Instrument [Line Items]
Interest rate		4.35%
Maturity Date		2064
Principal amounts outstanding		$ 250,000,000	250,000,000
Securitization bonds \| Securitization Bonds 3.057% Due 2020-2029 \| Consumers Energy Company
Debt Instrument [Line Items]
Maturity Date		2020-2029
Principal amounts outstanding		$ 277,000,000	$ 302,000,000
Weighted average interest rate		3.057%	2.913%
Revolving credit agreements \| Revolving credit agreements \| Consumers Energy Company
Debt Instrument [Line Items]
Maturity Date		2020-2023
Principal amounts outstanding		$ 215,000,000	$ 0
Weighted average interest rate		3.331%
Amount outstanding			0
CMS Energy
Debt Instrument [Line Items]
Principal amounts outstanding		$ 2,965,000,000	3,080,000,000
Long-term debt		$ 2,750,000,000	2,830,000,000
CMS Energy \| Senior Notes 8.750% Due 2019
Debt Instrument [Line Items]
Interest rate		8.75%
CMS Energy \| Senior Notes 6.250% Due 2020
Debt Instrument [Line Items]
Interest rate		6.25%
CMS Energy \| Senior Notes 2.950% Due 2027
Debt Instrument [Line Items]
Interest rate		2.95%
Maturity Date		2027
Principal amounts outstanding		$ 275,000,000	275,000,000
CMS Energy \| Senior notes
Debt Instrument [Line Items]
Principal amounts outstanding		$ 2,275,000,000	2,675,000,000
CMS Energy \| Senior notes \| Senior Notes 8.750% Due 2019
Debt Instrument [Line Items]
Interest rate		8.75%
Maturity Date		2019
Principal amounts outstanding		$ 0	100,000,000
CMS Energy \| Senior notes \| Senior Notes 6.250% Due 2020
Debt Instrument [Line Items]
Interest rate		6.25%
Maturity Date		2020
Principal amounts outstanding		$ 0	300,000,000
CMS Energy \| Senior notes \| Senior Notes 5.050% Due 2022
Debt Instrument [Line Items]
Interest rate		5.05%
Maturity Date		2022
Principal amounts outstanding		$ 300,000,000	300,000,000
CMS Energy \| Senior notes \| Senior Notes 3.875% Due 2024
Debt Instrument [Line Items]
Interest rate		3.875%
Maturity Date		2024
Principal amounts outstanding		$ 250,000,000	250,000,000
CMS Energy \| Senior notes \| Senior Notes 3.600% Due 2025
Debt Instrument [Line Items]
Interest rate		3.60%
Maturity Date		2025
Principal amounts outstanding		$ 250,000,000	250,000,000
CMS Energy \| Senior notes \| Senior Notes 3.000% Due 2026
Debt Instrument [Line Items]
Interest rate		3.00%
Maturity Date		2026
Principal amounts outstanding		$ 300,000,000	300,000,000
CMS Energy \| Senior notes \| Senior Notes 3.450% Due 2027
Debt Instrument [Line Items]
Interest rate		3.45%
Maturity Date		2027
Principal amounts outstanding		$ 350,000,000	350,000,000
CMS Energy \| Senior notes \| Senior Notes 4.700% Due 2043
Debt Instrument [Line Items]
Interest rate		4.70%
Maturity Date		2043
Principal amounts outstanding		$ 250,000,000	250,000,000
CMS Energy \| Senior notes \| Senior Notes 4.875% Due 2044
Debt Instrument [Line Items]
Interest rate		4.875%
Maturity Date		2044
Principal amounts outstanding		$ 300,000,000	300,000,000
CMS Energy \| Term loans and revolving credit agreements
Debt Instrument [Line Items]
Principal amounts outstanding		$ 210,000,000	405,000,000
CMS Energy \| Term loans and revolving credit agreements \| Term Loan Facility Due 2019
Debt Instrument [Line Items]
Maturity Date		2019
Principal amounts outstanding		$ 180,000,000	405,000,000
Three-month LIBOR plus a spread		0.80%
Interest rate at period end		3.322%
CMS Energy \| Term loans and revolving credit agreements \| Term Loan Facility Due 2023
Debt Instrument [Line Items]
Three-month LIBOR plus a spread		0.125%
Interest rate at period end		3.669%
CMS Energy \| Junior subordinated notes
Debt Instrument [Line Items]
Principal amounts outstanding		$ 480,000,000	0
CMS Energy \| Junior subordinated notes \| Junior Notes 5.625% Due 2078
Debt Instrument [Line Items]
Interest rate		5.625%
Maturity Date		2078
Principal amounts outstanding		$ 200,000,000	0
CMS Energy \| Junior subordinated notes \| Junior Notes 5.875% Due 2078
Debt Instrument [Line Items]
Interest rate		5.875%
Maturity Date		2078
Principal amounts outstanding		$ 280,000,000	0
CMS Energy \| Revolving credit agreements \| Revolving Credit Facilities June 5, 2023
Debt Instrument [Line Items]
Maturity Date		2023
Principal amounts outstanding		$ 30,000,000	$ 0
Scenario, Forecast \| Term loans and revolving credit agreements
Debt Instrument [Line Items]
Three-month LIBOR plus a spread	1.75%
Fixed interest rate	4.952%