XML 94 R81.htm IDEA: XBRL DOCUMENT
v3.8.0.1

SUPPLEMENTAL CASH FLOW INFORMATION - ADOPTION OF ACCOUNTING STANDARDS (Details) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2018 USD ($) Provisions | Mar. 31, 2017 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($)
Operating activities |  |  |  |  |
Other current assets | $ 81.3 | $ 41.2 | $ (7.1) | $ 103.2 | $ (27.2)
Other, net | 134.3 | (19.2) | (197.4) | (53.6) | (207.6)
Net cash provided by operating activities | 894.0 | 714.6 | 2,078.6 | 2,103.8 | 1,295.1
Investing activities |  |  |  |  |
Withdrawal of restricted cash from rabbi trust for qualifying payments |  |  | 0.0 | 0.0 | 0.0
Proceeds from the sale of investments held in rabbi trust | 16.5 | 8.6 | 8.7 | 1.7 | 126.9
Purchase of investments held in rabbi trust |  |  | (3.7) | (59.2) | (60.2)
Integrys acquisition, net of cash acquired |  |  | 0.0 | 0.0 | (1,299.1)
Other, net | (0.7) | 2.5 | 12.0 | 3.0 | 55.8
Net cash used in investing activities | (435.8) | (333.1) | (2,254.1) | (1,354.2) | (2,422.6)
Financing activities |  |  |  |  |
Other, net | (0.3) | (0.6) | (6.5) | (13.6) | 3.7
Net cash provided by (used in) financing activities | (445.1) | (380.8) | 161.4 | (845.7) | 1,234.4
Net change in cash, cash equivalents, and restricted cash | 13.1 | 0.7 | (14.1) | (96.1) | 106.9
Cash, cash equivalents, and restricted cash at beginning of period | 58.6 | 72.7 | 72.7 | 168.8 | 61.9
Cash, cash equivalents, and restricted cash at end of period | 71.7 | 73.4 | 58.6 | 72.7 | 168.8
2017 Form 10-K Cash Flows |  |  |  |  |
Operating activities |  |  |  |  |
Other current assets |  |  | (6.0) | 103.1 | (27.2)
Other, net |  |  | (197.5) | (53.8) | (209.1)
Net cash provided by operating activities |  |  | 2,079.6 | 2,103.5 | 1,293.6
Investing activities |  |  |  |  |
Withdrawal of restricted cash from rabbi trust for qualifying payments |  |  | 19.5 | 26.6 | 1.4
Proceeds from the sale of investments held in rabbi trust |  |  | 0.0 | 0.0 | 0.0
Purchase of investments held in rabbi trust |  |  | 0.0 | 0.0 | 0.0
Integrys acquisition, net of cash acquired |  |  | 0.0 | 0.0 | (1,329.9)
Other, net |  |  | 12.0 | 3.0 | 57.0
Net cash used in investing activities |  |  | (2,239.6) | (1,270.1) | (2,517.5)
Financing activities |  |  |  |  |
Other, net |  |  | (6.5) | (13.6) | (18.9)
Net cash provided by (used in) financing activities |  |  | 161.4 | (845.7) | 1,211.8
Net change in cash, cash equivalents, and restricted cash |  |  | 1.4 | (12.3) | (12.1)
Cash, cash equivalents, and restricted cash at beginning of period | 38.9 | 37.5 | 37.5 | 49.8 | 61.9
Cash, cash equivalents, and restricted cash at end of period |  |  | 38.9 | 37.5 | 49.8
Accounting Standards Update 2016-18 | Impact of ASU 2016-18 |  |  |  |  |
Operating activities |  |  |  |  |
Other current assets |  |  | (1.1) | 0.1 | 0.0
Other, net |  |  | 0.1 | 0.2 | 1.5
Net cash provided by operating activities |  |  | (1.0) | 0.3 | 1.5
Investing activities |  |  |  |  |
Withdrawal of restricted cash from rabbi trust for qualifying payments |  |  | (19.5) | (26.6) | (1.4)
Proceeds from the sale of investments held in rabbi trust |  |  | 8.7 | 1.7 | 126.9
Purchase of investments held in rabbi trust |  |  | (3.7) | (59.2) | (60.2)
Integrys acquisition, net of cash acquired |  |  | 0.0 | 0.0 | 30.8
Other, net |  |  | 0.0 | 0.0 | (1.2)
Net cash used in investing activities |  | (7.5) | (14.5) | (84.1) | 94.9
Financing activities |  |  |  |  |
Other, net |  |  | 0.0 | 0.0 | 22.6
Net cash provided by (used in) financing activities |  |  | 0.0 | 0.0 | 22.6
Net change in cash, cash equivalents, and restricted cash |  |  | (15.5) | (83.8) | 119.0
Cash, cash equivalents, and restricted cash at beginning of period | $ 19.7 | 35.2 | 35.2 | 119.0 | 0.0
Cash, cash equivalents, and restricted cash at end of period |  |  | $ 19.7 | $ 35.2 | $ 119.0
Accounting Standards Update 2016-15 |  |  |  |  |
Adoption of ASU 2016-15 |  |  |  |  |
Number of provisions in ASU 2016-15 | Provisions | 8 |  |  |  |
Impact on financial statements from adoption | $ 0.0 | $ 0.0 |  |  |

X
- Definition Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage. Excludes amount for disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3521-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=98513485&loc=SL98516268-108586 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3044-108585 + Details
Name: | us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of increase (decrease) in cash, cash equivalents, and cash and cash equivalents restricted to withdrawal or usage; including effect from exchange rate change. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 230 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=98513438&loc=d3e33268-110906 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3521-108585 + Details
Name: | us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash inflow associated with funds that are not available for withdrawal or use (such as funds held in escrow) and are associated with underlying transactions that are classified as investing activities. + References No definition available. + Details
Name: | us-gaap_DecreaseInRestrictedCash
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase (decrease) in current assets classified as other. + References No definition available. + Details
Name: | us-gaap_IncreaseDecreaseInOtherCurrentAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3521-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 26 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3574-108585 + Details
Name: | us-gaap_NetCashProvidedByUsedInFinancingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3521-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 26 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3574-108585 + Details
Name: | us-gaap_NetCashProvidedByUsedInInvestingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3521-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3536-108585 + Details
Name: | us-gaap_NetCashProvidedByUsedInOperatingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the quantification of the effect of adopting the new accounting standard or change in accounting principle expected by the entity to have a significant effect on the entity's financial statements. + References No definition available. + Details
Name: | us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_NewAccountingPronouncementsAndChangesInAccountingPrinciplesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Other cash or noncash adjustments to reconcile net income to cash provided by (used in) operating activities that are not separately disclosed in the statement of cash flows (for example, cash received or cash paid during the current period for miscellaneous operating activities, net change during the reporting period in other assets or other liabilities). + References No definition available. + Details
Name: | us-gaap_OtherOperatingActivitiesCashFlowStatement
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash (inflow) outflow from investing activities classified as other. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3098-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3095-108585 + Details
Name: | us-gaap_PaymentsForProceedsFromOtherInvestingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Cash outflow for purchase of trading, available-for-sale securities and held-to-maturity securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=82896770&loc=d3e26853-111562 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (a),(b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireMarketableSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) from financing activities classified as other. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3095-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3098-108585 + Details
Name: | us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash inflow associated with the sale of investments that are pledged or subject to withdrawal restrictions during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585 + Details
Name: | us-gaap_ProceedsFromSaleOfRestrictedInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of provisions included in a new accounting standards update. + References No definition available. + Details
Name: | wec_NumberOfProvisionInAccountingStandardsUpdate
Namespace Prefix: | wec_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_ScenarioPreviouslyReportedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201618Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_RestatementAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201615Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |