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Related Parties (Tables) | 6 Months Ended
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Jun. 30, 2020
Related Party Transactions [Line Items] |
Services Provided, Sales Credited And Purchases | The amounts billed for services provided, sales credited and purchases for the three and six months ended June 30 were as follows (in millions):
| IPL |  | WPL
| Three Months |  | Six Months |  | Three Months |  | Six Months
| 2020 |  | 2019 |  | 2020 |  | 2019 |  | 2020 |  | 2019 |  | 2020 |  | 2019
Corporate Services billings |  | $44 |  |  |  | $47 |  |  |  | $81 |  |  |  | $90 |  |  |  | $35 |  |  |  | $35 |  |  |  | $67 |  |  |  | $68 |
Sales credited | 10 |  |  | 12 |  |  | 25 |  |  | 27 |  |  | 2 |  |  | 3 |  |  | 4 |  |  | 4 |
Purchases billed | 57 |  |  | 74 |  |  | 138 |  |  | 158 |  |  | 20 |  |  | 29 |  |  | 40 |  |  | 59 |
Net Intercompany Payables | Net intercompany payables to Corporate Services were as follows (in millions):
| IPL |  | WPL
| June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019
Net payables to Corporate Services | $93 |  | $112 |  | $65 |  | $85
Related Amounts Billed Between Parties | The related amounts billed between the parties for the three and six months ended June 30 were as follows (in millions):
| Three Months |  | Six Months
| 2020 |  | 2019 |  | 2020 |  | 2019
ATC billings to WPL |  | $25 |  |  |  | $27 |  |  |  | $53 |  |  |  | $54 |
WPL billings to ATC | 3 |  |  | 3 |  |  | 6 |  |  | 7 |
IPL [Member] |
Related Party Transactions [Line Items] |
Services Provided, Sales Credited And Purchases | The amounts billed for services provided, sales credited and purchases for the three and six months ended June 30 were as follows (in millions):
| IPL |  | WPL
| Three Months |  | Six Months |  | Three Months |  | Six Months
| 2020 |  | 2019 |  | 2020 |  | 2019 |  | 2020 |  | 2019 |  | 2020 |  | 2019
Corporate Services billings |  | $44 |  |  |  | $47 |  |  |  | $81 |  |  |  | $90 |  |  |  | $35 |  |  |  | $35 |  |  |  | $67 |  |  |  | $68 |
Sales credited | 10 |  |  | 12 |  |  | 25 |  |  | 27 |  |  | 2 |  |  | 3 |  |  | 4 |  |  | 4 |
Purchases billed | 57 |  |  | 74 |  |  | 138 |  |  | 158 |  |  | 20 |  |  | 29 |  |  | 40 |  |  | 59 |
Net Intercompany Payables | Net intercompany payables to Corporate Services were as follows (in millions):
| IPL |  | WPL
| June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019
Net payables to Corporate Services | $93 |  | $112 |  | $65 |  | $85
WPL [Member] |
Related Party Transactions [Line Items] |
Services Provided, Sales Credited And Purchases | The amounts billed for services provided, sales credited and purchases for the three and six months ended June 30 were as follows (in millions):
| IPL |  | WPL
| Three Months |  | Six Months |  | Three Months |  | Six Months
| 2020 |  | 2019 |  | 2020 |  | 2019 |  | 2020 |  | 2019 |  | 2020 |  | 2019
Corporate Services billings |  | $44 |  |  |  | $47 |  |  |  | $81 |  |  |  | $90 |  |  |  | $35 |  |  |  | $35 |  |  |  | $67 |  |  |  | $68 |
Sales credited | 10 |  |  | 12 |  |  | 25 |  |  | 27 |  |  | 2 |  |  | 3 |  |  | 4 |  |  | 4 |
Purchases billed | 57 |  |  | 74 |  |  | 138 |  |  | 158 |  |  | 20 |  |  | 29 |  |  | 40 |  |  | 59 |
Net Intercompany Payables | Net intercompany payables to Corporate Services were as follows (in millions):
| IPL |  | WPL
| June 30, 2020 |  | December 31, 2019 |  | June 30, 2020 |  | December 31, 2019
Net payables to Corporate Services | $93 |  | $112 |  | $65 |  | $85
Related Amounts Billed Between Parties | The related amounts billed between the parties for the three and six months ended June 30 were as follows (in millions):
| Three Months |  | Six Months
| 2020 |  | 2019 |  | 2020 |  | 2019
ATC billings to WPL |  | $25 |  |  |  | $27 |  |  |  | $53 |  |  |  | $54 |
WPL billings to ATC | 3 |  |  | 3 |  |  | 6 |  |  | 7 |

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