​

December 31, 

​

June 30, 

​

2024

2025

​

​

(In millions)

Asset retirement obligations

​

$

14.3

​

$

16.2

Accrued postretirement benefits

​

​

5.9

​

​

6.2

Employee benefits

​

4.5

​

5.0

Earn-out liability

​

​

4.3

​

​

4.6

Other

​

2.7

​

2.8

Total

​

$

31.7

​

$

34.8