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Debt (Tables) | 6 Months Ended
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Jun. 30, 2019
Short-term Debt [Line Items] |
Other Short-Term Borrowings | Information regarding commercial paper classified as short-term debt was as follows (dollars in millions):
June 30, 2019 | Alliant Energy |  | IPL |  | WPL
Commercial paper outstanding | $390.5 |  | $— |  | $—
Commercial paper weighted average interest rates | 2.6% |  | N/A |  | N/A
Available credit facility capacity | $609.5 |  | $250.0 |  | $300.0
| Alliant Energy |  | IPL |  | WPL
Three Months Ended June 30 | 2019 |  | 2018 |  | 2019 |  | 2018 |  | 2019 |  | 2018
Maximum amount outstanding (based on daily outstanding balances) | $590.2 |  | $446.5 |  | $— |  | $31.4 |  | $193.3 |  | $109.4
Average amount outstanding (based on daily outstanding balances) | $531.7 |  | $234.5 |  | $— |  | $5.1 |  | $141.6 |  | $45.2
Weighted average interest rates | 2.7% |  | 2.2% |  | N/A |  | 2.3% |  | 2.5% |  | 1.8%
Six Months Ended June 30 |  |  |  |  |  |  |  |  |  |  |
Maximum amount outstanding (based on daily outstanding balances) | $600.6 |  | $446.5 |  | $50.4 |  | $31.4 |  | $195.1 |  | $109.4
Average amount outstanding (based on daily outstanding balances) | $515.4 |  | $272.1 |  | $0.3 |  | $2.6 |  | $139.8 |  | $28.4
Weighted average interest rates | 2.7% |  | 2.0% |  | 2.8% |  | 2.3% |  | 2.5% |  | 1.8%
IPL [Member] |
Short-term Debt [Line Items] |
Other Short-Term Borrowings | Information regarding commercial paper classified as short-term debt was as follows (dollars in millions):
June 30, 2019 | Alliant Energy |  | IPL |  | WPL
Commercial paper outstanding | $390.5 |  | $— |  | $—
Commercial paper weighted average interest rates | 2.6% |  | N/A |  | N/A
Available credit facility capacity | $609.5 |  | $250.0 |  | $300.0
| Alliant Energy |  | IPL |  | WPL
Three Months Ended June 30 | 2019 |  | 2018 |  | 2019 |  | 2018 |  | 2019 |  | 2018
Maximum amount outstanding (based on daily outstanding balances) | $590.2 |  | $446.5 |  | $— |  | $31.4 |  | $193.3 |  | $109.4
Average amount outstanding (based on daily outstanding balances) | $531.7 |  | $234.5 |  | $— |  | $5.1 |  | $141.6 |  | $45.2
Weighted average interest rates | 2.7% |  | 2.2% |  | N/A |  | 2.3% |  | 2.5% |  | 1.8%
Six Months Ended June 30 |  |  |  |  |  |  |  |  |  |  |
Maximum amount outstanding (based on daily outstanding balances) | $600.6 |  | $446.5 |  | $50.4 |  | $31.4 |  | $195.1 |  | $109.4
Average amount outstanding (based on daily outstanding balances) | $515.4 |  | $272.1 |  | $0.3 |  | $2.6 |  | $139.8 |  | $28.4
Weighted average interest rates | 2.7% |  | 2.0% |  | 2.8% |  | 2.3% |  | 2.5% |  | 1.8%
WPL [Member] |
Short-term Debt [Line Items] |
Other Short-Term Borrowings | Information regarding commercial paper classified as short-term debt was as follows (dollars in millions):
June 30, 2019 | Alliant Energy |  | IPL |  | WPL
Commercial paper outstanding | $390.5 |  | $— |  | $—
Commercial paper weighted average interest rates | 2.6% |  | N/A |  | N/A
Available credit facility capacity | $609.5 |  | $250.0 |  | $300.0
| Alliant Energy |  | IPL |  | WPL
Three Months Ended June 30 | 2019 |  | 2018 |  | 2019 |  | 2018 |  | 2019 |  | 2018
Maximum amount outstanding (based on daily outstanding balances) | $590.2 |  | $446.5 |  | $— |  | $31.4 |  | $193.3 |  | $109.4
Average amount outstanding (based on daily outstanding balances) | $531.7 |  | $234.5 |  | $— |  | $5.1 |  | $141.6 |  | $45.2
Weighted average interest rates | 2.7% |  | 2.2% |  | N/A |  | 2.3% |  | 2.5% |  | 1.8%
Six Months Ended June 30 |  |  |  |  |  |  |  |  |  |  |
Maximum amount outstanding (based on daily outstanding balances) | $600.6 |  | $446.5 |  | $50.4 |  | $31.4 |  | $195.1 |  | $109.4
Average amount outstanding (based on daily outstanding balances) | $515.4 |  | $272.1 |  | $0.3 |  | $2.6 |  | $139.8 |  | $28.4
Weighted average interest rates | 2.7% |  | 2.0% |  | 2.8% |  | 2.3% |  | 2.5% |  | 1.8%

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- Definition Tabular disclosure of short-term debt arrangements (having initial terms of repayment within one year or the normal operating cycle, if longer) including: (1) description of the short-term debt arrangement; (2) identification of the lender or type of lender; (3) repayment terms; (4) weighted average interest rate; (5) carrying amount of funds borrowed under the specified short-term debt arrangement as of the balance sheet date; (6) description of the refinancing of a short-term obligation when that obligation is excluded from current liabilities in the balance sheet; and (7) amount of a short-term obligation that has been excluded from current liabilities in the balance sheet because of a refinancing of the obligation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- 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
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