Note 5 - Other Income (Details Textual) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||||
|---|---|---|---|---|---|---|
Sep. 30, 2023 |
Sep. 30, 2022 |
Sep. 30, 2023 |
Sep. 30, 2022 |
|||
| Profit (Loss) from Real Estate Operations | [1] | $ 90 | $ 103 | $ 335 | $ 309 | |
| Real Estate Transaction [Member] | ||||||
| Profit (Loss) from Real Estate Operations | $ 107 | |||||
| Land [Member] | Colorado Department of Transportation [Member] | ||||||
| Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property | $ 35 | |||||
| Land [Member] | Illinois State Toll Highway Authority [Member] | ||||||
| Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property | $ 79 | |||||
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