XML 26 R10.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Consolidated Statements of Capitalization - USD ($) $ in Millions | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Common shareholder's equity | $ 9,491.8 | $ 8,960.2
Preferred stock of subsidiary | 30.4 | 30.4
Obligations under capital leases | 27.0 | 29.6
Total | 9,627.9 | 9,352.0
Integrys acquisition fair value adjustment | 26.9 | 33.3
Unamortized debt issuance costs | (38.0) | (38.1)
Unamortized discount, net and other | (28.1) | (31.8)
Total long-term debt, including current portion | 9,588.7 | 9,315.4
Current portion of long-term debt and capital lease obligations | (842.1) | (157.2)
Total long-term debt | 8,746.6 | 9,158.2
Total long-term capitalization | $ 18,238.4 | $ 18,118.4
WEC Energy Group Junior Notes (unsecured), 3.53% due 2067 |  |
Interest rate, (as a percent) | 3.53% |
Integrys Junior Notes (unsecured), 3.60% due 2066 |  |
Interest rate, (as a percent) | 3.60% | 3.05%
WE | WE Debentures (unsecured), 1.70% due 2018 |  |
Interest rate, (as a percent) | 1.70% |
Long-Term debt, Unsecured | $ 250.0 | $ 250.0
WE | WE Debentures (unsecured), 4.25% due 2019 |  |
Interest rate, (as a percent) | 4.25% |
Long-Term debt, Unsecured | $ 250.0 | 250.0
WE | WE Debentures (unsecured), 2.95% due 2021 |  |
Interest rate, (as a percent) | 2.95% |
Long-Term debt, Unsecured | $ 300.0 | 300.0
WE | WE Debentures (unsecured), 3.10% due 2025 |  |
Interest rate, (as a percent) | 3.10% |
Long-Term debt, Unsecured | $ 250.0 | 250.0
WE | WE Debentures (unsecured), 6.50% due 2028 |  |
Interest rate, (as a percent) | 6.50% |
Long-Term debt, Unsecured | $ 150.0 | 150.0
WE | WE Debentures (unsecured), 5.625% due 2033 |  |
Interest rate, (as a percent) | 5.625% |
Long-Term debt, Unsecured | $ 335.0 | 335.0
WE | WE Debentures (unsecured), 5.70% due 2036 |  |
Interest rate, (as a percent) | 5.70% |
Long-Term debt, Unsecured | $ 300.0 | 300.0
WE | WE Debentures (unsecured), 3.65% due 2042 |  |
Interest rate, (as a percent) | 3.65% |
Long-Term debt, Unsecured | $ 250.0 | 250.0
WE | WE Debentures (unsecured), 4.25% due 2044 |  |
Interest rate, (as a percent) | 4.25% |
Long-Term debt, Unsecured | $ 250.0 | 250.0
WE | WE Debentures (unsecured), 4.30% due 2045 |  |
Interest rate, (as a percent) | 4.30% |
Long-Term debt, Unsecured | $ 250.0 | 250.0
WE | WE Debentures (unsecured), 6.875% due 2095 |  |
Interest rate, (as a percent) | 6.875% |
Long-Term debt, Unsecured | $ 100.0 | 100.0
WPS | WPS Senior Notes (unsecured), 5.65% due 2017 |  |
Interest rate, (as a percent) | 5.65% |
Long-Term debt, Unsecured | $ 0.0 | 125.0
WPS | WPS Senior Notes (unsecured), 1.65% due 2018 |  |
Interest rate, (as a percent) | 1.65% |
Long-Term debt, Unsecured | $ 250.0 | 250.0
WPS | WPS Senior Notes (unsecured), 6.08% due 2028 |  |
Interest rate, (as a percent) | 6.08% |
Long-Term debt, Unsecured | $ 50.0 | 50.0
WPS | WPS Senior Notes (unsecured), 5.55% due 2036 |  |
Interest rate, (as a percent) | 5.55% |
Long-Term debt, Unsecured | $ 125.0 | 125.0
WPS | WPS Senior Notes (unsecured), 3.671% due 2042 |  |
Interest rate, (as a percent) | 3.671% |
Long-Term debt, Unsecured | $ 300.0 | 300.0
WPS | WPS Senior Notes (unsecured), 4.752% due 2044 |  |
Interest rate, (as a percent) | 4.752% |
Long-Term debt, Unsecured | $ 450.0 | 450.0
WG | WG Debentures (unsecured), 3.53% due 2025 |  |
Interest rate, (as a percent) | 3.53% |
Long-Term debt, Unsecured | $ 200.0 | 200.0
WG | WG Debentures (unsecured), 5.90% due 2035 |  |
Interest rate, (as a percent) | 5.90% |
Long-Term debt, Unsecured | $ 90.0 | 90.0
WG | WG Debentures (unsecured), 3.71% due 2046 |  |
Interest rate, (as a percent) | 3.71% |
Long-Term debt, Unsecured | $ 200.0 | 200.0
PGL | PGL First and Refunding Mortgage Bonds (secured), 8.00% due 2018 |  |
Interest rate, (as a percent) | 8.00% |
Long-Term debt, Secured | $ 5.0 | 5.0
PGL | PGL First and Refunding Mortgage Bonds (secured), 4.63% due 2019 |  |
Interest rate, (as a percent) | 4.63% |
Long-Term debt, Secured | $ 75.0 | 75.0
PGL | PGL First and Refunding Mortgage Bonds (secured), 3.90% due 2030 |  |
Interest rate, (as a percent) | 3.90% |
Long-Term debt, Secured | $ 50.0 | 50.0
PGL | PGL First and Refunding Mortgage Bonds (secured), 1.875% due 2033 |  |
Interest rate, (as a percent) | 1.875% |
Long-Term debt, Secured | $ 50.0 | 50.0
PGL | PGL First and Refunding Mortgage Bonds (secured), 4.0% due 2033 |  |
Interest rate, (as a percent) | 4.00% |
Long-Term debt, Secured | $ 50.0 | 50.0
PGL | PGL First and Refunding Mortgage Bonds (secured), 3.98% due 2042 |  |
Interest rate, (as a percent) | 3.98% |
Long-Term debt, Secured | $ 100.0 | 100.0
PGL | PGL First and Refunding Mortgage Bonds (secured), 3.96% due 2043 |  |
Interest rate, (as a percent) | 3.96% |
Long-Term debt, Secured | $ 220.0 | 220.0
PGL | PGL First and Refunding Mortgage Bonds (secured), 4.21% due 2044 |  |
Interest rate, (as a percent) | 4.21% |
Long-Term debt, Secured | $ 200.0 | 200.0
PGL | PGL First and Refunding Mortgage Bonds (secured), 3.65% due 2046 |  |
Interest rate, (as a percent) | 3.65% |
Long-Term debt, Secured | $ 50.0 | 50.0
PGL | PGL First and Refunding Mortgage Bonds (secured), 3.65% due 2046 |  |
Interest rate, (as a percent) | 3.65% |
Long-Term debt, Secured | $ 150.0 | 150.0
PGL | PGL First and Refunding Mortgage Bonds (secured), 3.77% due 2047 |  |
Interest rate, (as a percent) | 3.77% |
Long-Term debt, Secured | $ 100.0 | 0.0
NSG | NSG First Mortgage Bonds (secured), 3.43% due 2027 |  |
Interest rate, (as a percent) | 3.43% |
Long-Term debt, Secured | $ 28.0 | 28.0
NSG | NSG First Mortgage Bonds (secured), 3.96% due 2043 |  |
Interest rate, (as a percent) | 3.96% |
Long-Term debt, Secured | $ 54.0 | 54.0
MGU | MGU Senior Notes (unsecured), 3.11% due 2027 |  |
Interest rate, (as a percent) | 3.11% |
Long-Term debt, Unsecured | $ 30.0 | 0.0
MGU | MGU Senior Notes (unsecured), 3.41% due 2032 |  |
Interest rate, (as a percent) | 3.41% |
Long-Term debt, Unsecured | $ 30.0 | 0.0
MGU | MGU Senior Notes (unsecured), 4.01% due 2047 |  |
Interest rate, (as a percent) | 4.01% |
Long-Term debt, Unsecured | $ 30.0 | 0.0
MERC | MERC Senior Notes (unsecured), 3.11% due 2027 |  |
Interest rate, (as a percent) | 3.11% |
Long-Term debt, Unsecured | $ 40.0 | 0.0
MERC | MERC Senior Notes (unsecured), 3.41% due 2032 |  |
Interest rate, (as a percent) | 3.41% |
Long-Term debt, Unsecured | $ 40.0 | 0.0
MERC | MERC Senior Notes (unsecured), 4.01% due 2047 |  |
Interest rate, (as a percent) | 4.01% |
Long-Term debt, Unsecured | $ 40.0 | 0.0
Bluewater Gas Storage, LLC | Bluewater Gas Storage Senior Notes (unsecured), 3.76% due 2047 |  |
Interest rate, (as a percent) | 3.76% |
Long-Term debt, Unsecured | $ 125.0 | 0.0
We Power | We Power Subsidiaries Notes (secured, nonrecourse), 4.91% due 2018-2030 |  |
Interest rate, (as a percent) | 4.91% |
Long-Term debt, Secured | $ 101.0 | 106.7
We Power | We Power Subsidiaries Notes (secured, nonrecourse), 5.209% due 2018-2030 |  |
Interest rate, (as a percent) | 5.209% |
Long-Term debt, Secured | $ 194.1 | 204.8
We Power | We Power Subsidiaries Notes (secured, nonrecourse), 4.673% due 2018-2031 |  |
Interest rate, (as a percent) | 4.673% |
Long-Term debt, Secured | $ 162.4 | 170.9
We Power | We Power Subsidiaries Notes (secured, nonrecourse), 6.00% due 2018-2033 |  |
Interest rate, (as a percent) | 6.00% |
Long-Term debt, Secured | $ 121.5 | 126.1
We Power | We Power Subsidiaries Notes (secured, nonrecourse), 6.09% due 2030-2040 |  |
Interest rate, (as a percent) | 6.09% |
Long-Term debt, Secured | $ 275.0 | 275.0
We Power | We Power Subsidiaries Notes (secured, nonrecourse), 5.848% due 2031-2041 |  |
Interest rate, (as a percent) | 5.848% |
Long-Term debt, Secured | $ 215.0 | 215.0
WECC | WECC Notes (unsecured), 6.94% due 2028 |  |
Interest rate, (as a percent) | 6.94% |
Long-Term debt, Unsecured | $ 50.0 | 50.0
Integrys Holding Inc | Integrys Senior Notes (unsecured), 4.17% due 2020 |  |
Interest rate, (as a percent) | 4.17% |
Long-Term debt, Unsecured | $ 250.0 | 250.0
Integrys Holding Inc | Integrys Junior Notes (unsecured), 3.60% due 2066 |  |
Interest rate, (as a percent) | 3.60% |
Long-Term debt, Unsecured | $ 114.9 | 114.9
Integrys Holding Inc | Integrys Junior Notes (unsecured), 6.00% due 2073 |  |
Interest rate, (as a percent) | 6.00% |
Long-Term debt, Unsecured | $ 400.0 | 400.0
Bostco | Other Notes (secured, nonrecourse), 4.81% due 2030 |  |
Interest rate, (as a percent) | 4.81% |
Long-Term debt, Secured | $ 0.0 | 2.0
WEC Energy Group |  |
Common shareholder's equity | $ 9,461.4 | 8,929.8
WEC Energy Group | WEC Energy Group Senior Notes (unsecured), 1.65%, due 2018 |  |
Interest rate, (as a percent) | 1.65% |
Long-Term debt, Unsecured | $ 300.0 | 300.0
WEC Energy Group | WEC Energy Group Senior Notes (unsecured), 2.45% due 2020 |  |
Interest rate, (as a percent) | 2.45% |
Long-Term debt, Unsecured | $ 400.0 | 400.0
WEC Energy Group | WEC Energy Group Senior Notes (unsecured), 3.55% due 2025 |  |
Interest rate, (as a percent) | 3.55% |
Long-Term debt, Unsecured | $ 500.0 | 500.0
WEC Energy Group | WEC Energy Group Senior Notes (unsecured), 6.20% due 2033 |  |
Interest rate, (as a percent) | 6.20% |
Long-Term debt, Unsecured | $ 200.0 | 200.0
WEC Energy Group | WEC Energy Group Junior Notes (unsecured), 3.53% due 2067 |  |
Interest rate, (as a percent) | 3.53% |
Long-Term debt, Unsecured | $ 500.0 | 500.0
Common shareholder's equity |  |
Common shareholder's equity | $ 9,461.4 | $ 8,929.8

X
- Definition Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84164817&loc=d3e45280-112737 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_CapitalLeaseObligations
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition This element represents the total consolidated (as applicable) capitalization of the entity which is comprised of its long-term debt and equity instruments. The table may be detailed by subsidiary (legal entity) and include information by type of debt or equity detailed by instrument. + References No definition available. + Details
Name: | us-gaap_CapitalizationLongtermDebtAndEquity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.13,16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_DebtAndCapitalLeaseObligations
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount, after accumulated amortization, of debt discount (premium). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28567-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399 + Details
Name: | us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of long-term debt and capital lease obligation due after one year or beyond the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebtAndCapitalLeaseObligations
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt and capital leases due within one year or the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.20) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt and capital lease obligations including current maturities. + References No definition available. + Details
Name: | us-gaap_LongTermDebtAndCapitalLeaseObligationsIncludingCurrentMaturities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Aggregate par or stated value of issued nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable preferred shares, par value and other disclosure concepts are in another section within stockholders' equity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_PreferredStockValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Carrying amount of collateralized debt obligations with maturities initially due after one year or beyond the operating cycle, if longer, excluding the current portion. Obligations include, but not limited to, mortgage loans, chattel loans, and other borrowings secured by assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_SecuredLongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(30)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 4.E) -URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(31)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockholdersEquity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_UnamortizedDebtIssuanceExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying value as of the balance sheet date of uncollateralized debt obligation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_UnsecuredLongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Integrys Fair Value Adjustment to Long-term Debt + References No definition available. + Details
Name: | wec_IntegrysFairValueAdjustmenttoLongtermDebt
Namespace Prefix: | wec_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_JuniorNotesUnsecured625Due2067Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_IntegrysJuniorNotesdue2066Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_WisconsinelectricMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WEDebenturesdue2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_DebenturesUnsecured425Due2019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WEDebenturesdue2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WEDebenturedue2025Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WEDebenturesdue2028Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WEDebenturesdue2033Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WEDebenturesdue2036Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WEDebenturesdue2042Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WEDebenturesdue2044Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WEDebenturedue2045Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WEDebenturesdue2095Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_WisconsinPublicServiceCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WPSSeniorNotesdue2017Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WPSSeniorNotesdue2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WPSSeniorNotesdue2028Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WPSSeniorNotesdue2036Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WPSSeniorNotesdue2042Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WPSSeniorNotesdue2044Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_WisconsinGasLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WGDebenturesdue2025Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WGDebenturesdue2035Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WGDebenturesdue2046Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_ThePeoplesGasLightAndCokeCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_PGLFirstandRefundingMortgageBondsdue2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_PGLFirstandRefundingMortgageBondsdue2019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_PGLFirstandRefundingMortgageBondsdue2030Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_PGLFirstandRefundingMortgageBondsdue2033Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_FirstAndRefundingMortgageBondsSeriesZz40BondsDue2033Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_PGLFirstandRefundingMortgageBondsdue2042Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_PGLFirstandRefundingMortgageBondsdue2043Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_PGLFirstandRefundingMortgageBondsdue2044Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_PGLFirstandRefundingMortgageBondsdue2046Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_BondsSeriesDDD3.65due2046Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_PGLFirstandRefundingMortgageBondsdue2047Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_NorthShoreGasCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_NSGFirstMortgageBondsdue2027Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_NSGFirstMortgageBondsdue2043Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_MGUMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_MGUSeniorNotes3.11dueJuly152027Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_MGUSeniorNotes3.41dueJuly152032Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_MGUSeniorNotes4.01dueJuly152047Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_MinnesotaEnergyResourcesCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_MERCSeniorNotes3.11dueJuly152027Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_MERCSeniorNotes3.41dueJuly152032Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_MERCSeniorNotes4.01dueJuly152047Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_BluewaterGasStorageLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_BluewaterGasStorageSeniorNotesdue2047Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_WePowerLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WEPowerSubsidiariesNotesdue20182030Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_Notessecurednonrecourse5.209due20132030MemberMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WePowerSubsidiariesNotesdue20182031Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WePowerSubsidiariesNotesdue20182033Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WePowerSubsidiariesNotesdue20302040Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WePowerSubsidiariesNotesdue20312041Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_WisconsinEnergyCapitalCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WECCNotesdue2028Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_IntegrysHoldingIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_IntegrysSeniorNotesdue2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_IntegrysJuniorNotesdue2073Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_BostcoLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_OtherNotesdue2030Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConsolidatedEntitiesAxis=us-gaap_ParentCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WECSeniorNotesdue2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WECEnergyGroupSeniorNotesdue2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WECEnergyGroupSeniorNotesdue2025Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=wec_WECEnergyGropuSeniorNotesdue2033Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_ParentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |