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Related Parties (Tables) | 12 Months Ended
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Dec. 31, 2019
Related Party Transaction [Line Items] |
Services Provided, Sales Credited And Purchases Billed | The amounts billed for services provided, sales credited and purchases were as follows (in millions):
| IPL |  | WPL
| 2019 |  | 2018 |  | 2017 |  | 2019 |  | 2018 |  | 2017
Corporate Services billings |  | $185 |  |  |  | $170 |  |  |  | $177 |  |  |  | $142 |  |  |  | $132 |  |  |  | $135 |
Sales credited | 68 |  |  | 48 |  | 23 |  | 7 |  |  | 28 |  | 13
Purchases billed | 331 |  |  | 358 |  | 364 |  | 120 |  |  | 81 |  | 115
Net Intercompany Payables | As of December 31, net intercompany payables to Corporate Services were as follows (in millions):
| 2019 |  | 2018
IPL |  | $112 |  |  |  | $95 |
WPL | 85 |  |  | 71 |
Related Amounts Billed Between Parties | The related amounts billed between the parties were as follows (in millions):
| 2019 |  | 2018 |  | 2017
ATC billings to WPL |  | $109 |  |  |  | $106 |  |  |  | $105 |
WPL billings to ATC | 13 |  |  | 11 |  |  | 10 |
IPL [Member] |
Related Party Transaction [Line Items] |
Services Provided, Sales Credited And Purchases Billed | The amounts billed for services provided, sales credited and purchases were as follows (in millions):
| IPL |  | WPL
| 2019 |  | 2018 |  | 2017 |  | 2019 |  | 2018 |  | 2017
Corporate Services billings |  | $185 |  |  |  | $170 |  |  |  | $177 |  |  |  | $142 |  |  |  | $132 |  |  |  | $135 |
Sales credited | 68 |  |  | 48 |  | 23 |  | 7 |  |  | 28 |  | 13
Purchases billed | 331 |  |  | 358 |  | 364 |  | 120 |  |  | 81 |  | 115
Net Intercompany Payables | As of December 31, net intercompany payables to Corporate Services were as follows (in millions):
| 2019 |  | 2018
IPL |  | $112 |  |  |  | $95 |
WPL | 85 |  |  | 71 |
WPL [Member] |
Related Party Transaction [Line Items] |
Services Provided, Sales Credited And Purchases Billed | The amounts billed for services provided, sales credited and purchases were as follows (in millions):
| IPL |  | WPL
| 2019 |  | 2018 |  | 2017 |  | 2019 |  | 2018 |  | 2017
Corporate Services billings |  | $185 |  |  |  | $170 |  |  |  | $177 |  |  |  | $142 |  |  |  | $132 |  |  |  | $135 |
Sales credited | 68 |  |  | 48 |  | 23 |  | 7 |  |  | 28 |  | 13
Purchases billed | 331 |  |  | 358 |  | 364 |  | 120 |  |  | 81 |  | 115
Net Intercompany Payables | As of December 31, net intercompany payables to Corporate Services were as follows (in millions):
| 2019 |  | 2018
IPL |  | $112 |  |  |  | $95 |
WPL | 85 |  |  | 71 |
Related Amounts Billed Between Parties | The related amounts billed between the parties were as follows (in millions):
| 2019 |  | 2018 |  | 2017
ATC billings to WPL |  | $109 |  |  |  | $106 |  |  |  | $105 |
WPL billings to ATC | 13 |  |  | 11 |  |  | 10 |

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