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v3.25.2

Other noncurrent liabilities (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2025
Other noncurrent liabilities |
Other noncurrent liabilities | ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ |  | December 31, |  | June 30,
​ | ​ | 2024 | ​ | 2025
​ | ​ | (In millions)
Accrued development costs | ​ | $ | 26.8 | ​ | $ | 24.7
Operating lease liabilities | ​ | ​ | 17.1 | ​ | ​ | 17.1
Insurance claims and expenses | ​ |  | 16.6 | ​ |  | 16.6
Asset retirement obligations | ​ | ​ | 14.3 | ​ | ​ | 16.2
Deferred income | ​ | ​ | 11.8 | ​ | ​ | 8.0
Other postretirement benefits | ​ |  | 6.7 | ​ |  | 7.0
Employee benefits | ​ |  | 4.5 | ​ |  | 5.0
Earn-out liability | ​ | ​ | 4.3 | ​ | ​ | 4.6
Other | ​ |  | .6 | ​ |  | .5
Total | ​ | $ | 102.7 | ​ | $ | 99.7

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