Income Taxes - Roll forward of interest accrued on unrecognized tax benefits (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Balance as of January 1	$ 0.5	$ 0.1	$ 0.5
Interest expense (income) related to unrecognized tax benefits	0.1	0.4	(0.4)
Balance as of December 31	0.6	0.5	0.1
Penalties in the consolidated income statements	0.0	0.0	$ 0.0
Accrued penalties on the consolidated balance sheets	0.0	$ 0.0
Unrecognized tax benefits, decrease resulting from statute of limitations	$ 0.6

No definition available.

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

- Definition

Amount of statutory penalties accrued for a tax position claimed or expected to be claimed by the entity, in its tax return.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-15

+ Details

Name:	us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAccrued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of expense for penalties related to a tax position claimed or expected to be claimed in the tax return.

+ References

+ Details

Name:	us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of interest expense accrued for an underpayment of income taxes.

+ References

+ Details

Name:	us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of interest expense for an underpayment of income taxes.

+ References

+ Details

Name:	us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Unrecognized tax benefits, decrease possible in the next 12 months resulting from statute of limitations

+ References

No definition available.

+ Details

Name:	wec_UnrecognizedTaxBenefitsDecreaseResultingFromStatuteOfLimitations
Namespace Prefix:	wec_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant