The per share price of the Company's stock at which the contract holder of the freestanding contract has the right to purchase or sell the Company's stock at a future date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 50
-Paragraph 5
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=126731327&loc=d3e90205-114008

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(1)
-URI https://asc.fasb.org/extlink&oid=109262807&loc=d3e22047-110879

+ Details

Name:	us-gaap_ForwardContractIndexedToIssuersEquityForwardRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum number of shares that could be issued to net share settle a contract, if applicable. If a contract does not have a fixed or determinable maximum number of shares that may be required to be issued, disclose the fact that a potentially infinite number of shares could be issued to settle the contract.

+ References

+ Details

Name:	us-gaap_ForwardContractIndexedToIssuersEquityShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- 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.

+ Details

Name:	us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_ForwardContractIndexedToIssuersEquityTypeAxis=cms_ForwardContractsEnteredIntoSeptember152020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ForwardContractIndexedToIssuersEquityTypeAxis=cms_ForwardContractsEnteredIntoDecember222020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ForwardContractIndexedToIssuersEquityTypeAxis=cms_ForwardContractsEnteredIntoAugust32022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ForwardContractIndexedToIssuersEquityTypeAxis=cms_ForwardContractsEnteredIntoAugust242022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ForwardContractIndexedToIssuersEquityTypeAxis=cms_ForwardContractsEnteredIntoAugust292022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Financings and Capitalization (Schedule of Forward Stock Contracts) (Details) - $ / shares	Sep. 30, 2022	Aug. 29, 2022	Aug. 24, 2022	Aug. 03, 2022	Dec. 22, 2020	Sep. 15, 2020
Forward contracts entered into 9/15/2020
Debt and Equity Securities, FV-NI [Line Items]
Number of Shares (in shares)						846,759
Initial forward price (in dollars per share)	$ 57.31					$ 61.04
Forward contracts entered into 12/22/2020
Debt and Equity Securities, FV-NI [Line Items]
Number of Shares (in shares)					115,595
Initial forward price (in dollars per share)	58.65				$ 61.81
Forward contracts entered into 8/3/2022
Debt and Equity Securities, FV-NI [Line Items]
Number of Shares (in shares)				2,944,207
Initial forward price (in dollars per share)	67.78			$ 67.59
Forward contracts entered into 8/24/2022
Debt and Equity Securities, FV-NI [Line Items]
Number of Shares (in shares)			1,677,938
Initial forward price (in dollars per share)	69.59		$ 69.46
Forward contracts entered into 8/29/2022
Debt and Equity Securities, FV-NI [Line Items]
Number of Shares (in shares)		1,783,388
Initial forward price (in dollars per share)	$ 68.29	$ 68.18