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Note 13 - Commitments and Contingencies (Tables) | 3 Months Ended
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Mar. 31, 2023
Notes Tables |
Schedule of Loss Contingencies by Contingency, Environmental [Table Text Block] |
Millions, for the Three Months Ended March 31, |  | 2023 |  |  | 2022 |
Beginning balance |  | $ | 253 |  |  | $ | 243 |
Accruals |  |  | 44 |  |  |  | 40 |
Payments |  |  | (26 | ) |  |  | (15 | )
Ending balance at March 31, |  | $ | 271 |  |  | $ | 268 |
Current portion, ending balance at March 31, |  | $ | 74 |  |  | $ | 64 |
Personal Injury [Member] |
Notes Tables |
Schedule of Loss Contingencies by Contingency [Table Text Block] |
Millions, for the Three Months Ended March 31, |  | 2023 |  |  | 2022 |
Beginning balance |  | $ | 361 |  |  | $ | 325 |
Current year accruals |  |  | 27 |  |  |  | 23 |
Changes in estimates for prior years |  |  | 7 |  |  |  | 6 |
Payments |  |  | (16 | ) |  |  | (22 | )
Ending balance at March 31, |  | $ | 379 |  |  | $ | 332 |
Current portion, ending balance at March 31, |  | $ | 84 |  |  | $ | 67 |

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