XML 101 R85.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Goodwill (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Goodwill |  |
Accumulated impairment losses | $ 0.0 |
Goodwill impairment loss | 0.0 |
Changes to goodwill balances by segment |  |
Goodwill balance as of January 1 | 3,046.2 | $ 3,023.5
Adjustment to Integrys purchase price allocation | 0.0 | 22.7
Acquisition of Bluewater | 7.3 | 0.0
Goodwill balance as of December 31 | 3,053.5 | 3,046.2
Wisconsin |  |
Changes to goodwill balances by segment |  |
Goodwill balance as of January 1 | 2,104.3 | 2,109.5
Adjustment to Integrys purchase price allocation | 0.0 | (5.2)
Acquisition of Bluewater | 0.0 | 0.0
Goodwill balance as of December 31 | 2,104.3 | 2,104.3
Illinois |  |
Changes to goodwill balances by segment |  |
Goodwill balance as of January 1 | 758.7 | 731.2
Adjustment to Integrys purchase price allocation | 0.0 | 27.5
Acquisition of Bluewater | 0.0 | 0.0
Goodwill balance as of December 31 | 758.7 | 758.7
Other States |  |
Changes to goodwill balances by segment |  |
Goodwill balance as of January 1 | 183.2 | 182.8
Adjustment to Integrys purchase price allocation | 0.0 | 0.4
Acquisition of Bluewater | 0.0 | 0.0
Goodwill balance as of December 31 | 183.2 | 183.2
Non-Utility Energy Infrastructure |  |
Changes to goodwill balances by segment |  |
Goodwill balance as of January 1 | 0.0 | 0.0
Adjustment to Integrys purchase price allocation | 0.0 | 0.0
Acquisition of Bluewater | 7.3 | 0.0
Goodwill balance as of December 31 | $ 7.3 | $ 0.0

X
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
Name: | us-gaap_GoodwillAcquiredDuringPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a,h) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
Name: | us-gaap_GoodwillImpairedAccumulatedImpairmentLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13854-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13777-109266 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
Name: | us-gaap_GoodwillImpairmentLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- 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_GoodwillLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e961-128460 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
Name: | us-gaap_GoodwillPurchaseAccountingAdjustments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_GoodwillRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=wec_WisconsinSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=wec_IllinoisMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=wec_OtherStatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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