Property, Plant, and Equipment - Balances (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Property, plant, and equipment
Accumulated depreciation	$ 9,889.3	$ 9,364.7
Net property, plant, and equipment	26,982.4	25,707.4
Columbia generating unit 1 \| WPS
Property, plant, and equipment
Net book value of plant to be retired	89.1
Columbia generating unit 2 \| WPS
Property, plant, and equipment
Net book value of plant to be retired	187.9
Regulated operations
Property, plant, and equipment
Accumulated depreciation	8,894.9	8,465.0
Net	21,957.4	20,631.9
CWIP	406.0	683.9
Net property, plant, and equipment	22,363.4	21,315.8
Regulated operations \| Electric - generation
Property, plant, and equipment
Property, plant, and equipment	6,981.4	7,015.3
Regulated operations \| Electric - distribution
Property, plant, and equipment
Property, plant, and equipment	7,854.7	7,455.5
Regulated operations \| Natural gas - distribution, storage, and transmission
Property, plant, and equipment
Property, plant, and equipment	13,526.6	12,730.0
Regulated operations \| Property, plant, and equipment to be retired, net
Property, plant, and equipment
Property, plant, and equipment to be retired, net	277.0	0.0
Regulated operations \| Other
Property, plant, and equipment
Property, plant, and equipment	2,212.6	1,896.1
Non-regulated operations
Property, plant, and equipment
Accumulated depreciation	994.4	899.7
Net	4,589.2	4,056.5
CWIP	29.8	335.1
Net property, plant, and equipment	4,619.0	4,391.6
Non-regulated operations \| Other
Property, plant, and equipment
Property, plant, and equipment	27.0	41.8
Non-regulated operations \| We Power generation
Property, plant, and equipment
Property, plant, and equipment	3,240.5	3,238.8
Non-regulated operations \| Renewable generation
Property, plant, and equipment
Property, plant, and equipment	1,837.5	1,213.3
Non-regulated operations \| Natural gas storage
Property, plant, and equipment
Property, plant, and equipment	289.9	250.0
Non-regulated operations \| Corporate services
Property, plant, and equipment
Property, plant, and equipment	188.7	212.3
Non-Utility Energy Infrastructure \| Non-regulated operations
Property, plant, and equipment
Property, plant, and equipment	$ 5,367.9	$ 4,702.1

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.14)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Amount of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

+ References

+ Details

Name:	us-gaap_ConstructionInProgressGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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

- Definition

Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(14))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(8))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 360
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124429447&loc=SL124453093-239630

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(13))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Period end amount of total net PPE.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of long-lived assets that will be abandoned, net of accumulated depreciation.

+ References

No definition available.

+ Details

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

- Definition

Gross amount of long-lived physical assets used in the normal conduct of business and not intended for resale. Amount excludes construction work in progress. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

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

- Definition

Long-lived physical assets that are held by an entity, excluding construction work in progress, for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=wec_ColumbiaEnergyCenterUnit1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=wec_WisconsinPublicServiceCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=wec_ColumbiaEnergyCenterUnit2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilityRegulatedOrUnregulatedStatusAxis=us-gaap_RegulatedOperationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_ElectricGenerationEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_ElectricDistributionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=wec_NaturalGasStorageTransportationandDistributionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=wec_PropertyplantandequipmenttobeabandonedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_PropertyPlantAndEquipmentOtherTypesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilityRegulatedOrUnregulatedStatusAxis=us-gaap_UnregulatedOperationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=wec_WePowerGeneratingFacilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=wec_RenewableGenerationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=wec_NaturalGasStorageEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=wec_CorporateServicesEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=wec_NonUtilityEnergyInfrastructureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: