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Shareholders' Equity (Tables) | 12 Months Ended
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Dec. 31, 2024
Stockholders' Equity Note [Abstract] |
Common stock reserved for conversion and incentive plans | The following shares of common stock were reserved as of December 31, 2024 (in millions):
GATX Corporation 2004 Equity Incentive Compensation Plan | 2.1 |
GATX Corporation 2012 Incentive Award Plan | 4.9 |
Total | 7.0 |

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