XML 53 R41.htm IDEA: XBRL DOCUMENT
v3.25.3

LONG-TERM DEBT (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2025
Long-Term Debt, Unclassified [Abstract] |
Schedule of convertible debt | The following is a summary of our convertible debt instruments as of September 30, 2025:
(in millions) |  | Principal Amount |  | Unamortized Debt Issuance Costs |  | Net Carrying Amount |  | Fair Value Amount (1)
2027 Notes |  | $ | 862.5 |  |  | $ | (5.5) |  |  | $ | 857.0 |  |  | $ | 1,034.6 |
2028 Notes |  | 900.0 |  |  | (9.4) |  |  | 890.6 |  |  | 928.3 |
2029 Notes |  | 862.5 |  |  | (7.3) |  |  | 855.2 |  |  | 1,056.6 |
(1) The fair values are categorized in Level 2 of the fair value hierarchy. See Note 13, Fair Value Measurements, for more information on the levels of the fair value hierarchy.
Schedule of convertible debt interest expense | The following table provides a summary of the interest expense recorded for each of the 2027 Notes, 2028 Notes, and 2029 Notes:
|  | Three Months Ended September 30 |  | Nine Months Ended September 30
(in millions) |  | 2025 |  | 2024 |  | 2025 |  | 2024
2027 Notes |  |  |  |  |  |  |  |
Contractual interest expense |  | $ | 9.4 |  |  | $ | 9.4 |  |  | $ | 28.3 |  |  | $ | 12.9 |
Amortization of debt issuance costs |  | 0.8 |  |  | 0.8 |  |  | 2.5 |  |  | 1.1 |
Total interest expense – 2027 Notes |  | 10.2 |  |  | 10.2 |  |  | 30.8 |  |  | 14.0 |
2028 Notes |  |  |  |  |  |  |  |
Contractual interest expense |  | 7.6 |  |  | — |  |  | 9.4 |  |  | — |
Amortization of debt issuance costs |  | 0.6 |  |  | — |  |  | 0.9 |  |  | — |
Total interest expense – 2028 Notes |  | $ | 8.2 |  |  | $ | — |  |  | $ | 10.3 |  |  | $ | — |
2029 Notes |  |  |  |  |  |  |  |
Contractual interest expense |  | 9.4 |  |  | 9.4 |  |  | 28.3 |  |  | 12.9 |
Amortization of debt issuance costs |  | 0.5 |  |  | 0.5 |  |  | 1.5 |  |  | 0.7 |
Total interest expense – 2029 Notes |  | $ | 9.9 |  |  | $ | 9.9 |  |  | $ | 29.8 |  |  | $ | 13.6 |

X
- Definition Tabular disclosure of convertible debt instrument. Includes, but is not limited to, principal amount and amortized premium or discount. + References No definition available. + Details
Name: | us-gaap_ConvertibleDebtTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Convertible Debt Interest Expense + References No definition available. + Details
Name: | wec_ConvertibleDebtInterestExpenseTableTextBlock
Namespace Prefix: | wec_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration