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Debt | 3 Months Ended
--- | ---
Mar. 31, 2022
Debt [Line Items] |
Debt | DEBT NOTE 6(a) Short-term Debt - Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper classified as short-term debt was as follows (dollars in millions):
March 31, 2022 | Alliant Energy |  | IPL |  | WPL
Amount outstanding | $276 |  | $— |  | $157
Weighted average interest rates | 0.6% |  | N/A |  | 0.5%
Available credit facility capacity | $724 |  | $250 |  | $143
| Alliant Energy |  | IPL |  | WPL
Three Months Ended March 31 | 2022 |  | 2021 |  | 2022 |  | 2021 |  | 2022 |  | 2021
Maximum amount outstanding (based on daily outstanding balances) | $577 |  | $578 |  | $— |  | $— |  | $252 |  | $275
Average amount outstanding (based on daily outstanding balances) | $443 |  | $424 |  | $— |  | $— |  | $205 |  | $189
Weighted average interest rates | 0.3% |  | 0.2% |  | —% |  | —% |  | 0.3% |  | 0.2%
NOTE 6(b) Long-term Debt - In February 2022, AEF issued $350 million of 3.6% senior notes due 2032. The net proceeds from the issuance were used to reduce Alliant Energy’s outstanding commercial paper and for general corporate purposes. In March 2022, AEF entered into a $300 million variable rate (1% as of March 31, 2022) term loan credit agreement (with Alliant Energy as guarantor), which expires in March 2024, and used the borrowings under this agreement to retire its $300 million variable rate term loan credit agreement that expired in March 2022.
IPL [Member] |
Debt [Line Items] |
Debt | DEBT NOTE 6(a) Short-term Debt - Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper classified as short-term debt was as follows (dollars in millions):
March 31, 2022 | Alliant Energy |  | IPL |  | WPL
Amount outstanding | $276 |  | $— |  | $157
Weighted average interest rates | 0.6% |  | N/A |  | 0.5%
Available credit facility capacity | $724 |  | $250 |  | $143
| Alliant Energy |  | IPL |  | WPL
Three Months Ended March 31 | 2022 |  | 2021 |  | 2022 |  | 2021 |  | 2022 |  | 2021
Maximum amount outstanding (based on daily outstanding balances) | $577 |  | $578 |  | $— |  | $— |  | $252 |  | $275
Average amount outstanding (based on daily outstanding balances) | $443 |  | $424 |  | $— |  | $— |  | $205 |  | $189
Weighted average interest rates | 0.3% |  | 0.2% |  | —% |  | —% |  | 0.3% |  | 0.2%
WPL [Member] |
Debt [Line Items] |
Debt | DEBT NOTE 6(a) Short-term Debt - Information regarding Alliant Energy’s, IPL’s and WPL’s commercial paper classified as short-term debt was as follows (dollars in millions):
March 31, 2022 | Alliant Energy |  | IPL |  | WPL
Amount outstanding | $276 |  | $— |  | $157
Weighted average interest rates | 0.6% |  | N/A |  | 0.5%
Available credit facility capacity | $724 |  | $250 |  | $143
| Alliant Energy |  | IPL |  | WPL
Three Months Ended March 31 | 2022 |  | 2021 |  | 2022 |  | 2021 |  | 2022 |  | 2021
Maximum amount outstanding (based on daily outstanding balances) | $577 |  | $578 |  | $— |  | $— |  | $252 |  | $275
Average amount outstanding (based on daily outstanding balances) | $443 |  | $424 |  | $— |  | $— |  | $205 |  | $189
Weighted average interest rates | 0.3% |  | 0.2% |  | —% |  | —% |  | 0.3% |  | 0.2%

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- Definition The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -URI http://asc.fasb.org/topic&trid=2208564 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1C -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1I -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1I -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(c)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1C -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1C -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1E -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1I -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 + Details
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