Commitments and Contingencies NSP-Minnesota-Sherco (Details) - USD ($) $ in Millions |
1 Months Ended | 9 Months Ended | |
|---|---|---|---|
Jan. 31, 2021 |
Sep. 30, 2024 |
May 17, 2024 |
|
| Rate Matters [Abstract] | |||
| Sherco Disallowance | $ 22 | ||
| ALJ Recommended Customer Refund | $ 34 | ||
| Disallowance Not Considered in ALJ Recommendation | $ 22 | ||
| 2011 Sherco Unit 3 Outage Refunds | $ 46 | ||
| NSP-Minnesota | |||
| Rate Matters [Abstract] | |||
| Customer refund of previously recovered purchased power costs | $ 17 |