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v3.19.1

Revenue Local Power Company Contracts (Details) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Mar. 31, 2019 USD ($) Customers percent | Mar. 31, 2018 USD ($) | Mar. 31, 2019 USD ($) Customers percent | Mar. 31, 2018 USD ($)
Long-term Contract for Purchase of Electric Power [Line Items] |  |  |  |
Total number of customers | 154 |  | 154 |
Long-Duration Contracts Revenue Recognition, Policy [Policy Text Block] | $ 2,750,000,000 | $ 2,792,000,000 | $ 5,475,000,000 | $ 5,341,000,000
Total number of customers that represent the percent of sales | percent | 1 |  | 1 |
Total long-duration contracts revenue recognition | 2,514,000,000 |  | 4,981,000,000 |
5-year Termination Notice [Member] |  |  |  |
Long-term Contract for Purchase of Electric Power [Line Items] |  |  |  |
Number of customers | Customers | 86 |  | 86 |
Number of customers that represent the percent of sales | percent | 1 |  | 1 |
Long-Duration Contracts Revenue Recognition, Policy [Policy Text Block] | $ 1,472,000,000 |  |  |
6-year Termination Notice [Member] |  |  |  |
Long-term Contract for Purchase of Electric Power [Line Items] |  |  |  |
Number of customers | Customers | 1 |  | 1 |
Number of customers that represent the percent of sales | percent | 0 |  | 0 |
Long-Duration Contracts Revenue Recognition, Policy [Policy Text Block] | $ 13,000,000 |  |  |
10-year Termination Notice [Member] |  |  |  |
Long-term Contract for Purchase of Electric Power [Line Items] |  |  |  |
Number of customers | Customers | 52 |  | 52 |
Number of customers that represent the percent of sales | percent | 0 |  | 0 |
Long-Duration Contracts Revenue Recognition, Policy [Policy Text Block] | $ 862,000,000 |  |  |
12-year Termination Notice [Member] |  |  |  |
Long-term Contract for Purchase of Electric Power [Line Items] |  |  |  |
Number of customers | Customers | 1 |  | 1 |
Number of customers that represent the percent of sales | percent | 0 |  | 0 |
Long-Duration Contracts Revenue Recognition, Policy [Policy Text Block] | $ 6,000,000 |  |  |
15-year Termination Notice [Member] |  |  |  |
Long-term Contract for Purchase of Electric Power [Line Items] |  |  |  |
Number of customers | Customers | 11 |  | 11 |
Number of customers that represent the percent of sales | percent | 0 |  | 0 |
Long-Duration Contracts Revenue Recognition, Policy [Policy Text Block] | $ 127,000,000 |  |  |
20-year Termination Notice [Member] |  |  |  |
Long-term Contract for Purchase of Electric Power [Line Items] |  |  |  |
Number of customers | Customers | 3 |  | 3 |
Number of customers that represent the percent of sales | percent | 0 |  | 0 |
Long-Duration Contracts Revenue Recognition, Policy [Policy Text Block] | $ 34,000,000 |  |  |

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