v3.26.1
SHORT-TERM INVESTMENTS: (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Short term investment:          
Trading securities $ 1,664.8   $ 1,664.8   $ 604.5
Weighted average interest rate (as a percent)     3.90%   4.10%
Available-for-sale 0.1   $ 0.1   $ 0.1
Weighted average interest rate (as a percent)     0.90%   0.90%
Total 1,664.9   $ 1,664.9   $ 604.6
Trading:          
Interest earned 20.4 $ 7.2 25.7 $ 9.5  
Maximum          
Trading:          
Unrealized gain (loss) at the end of the period $ 0.1 $ 0.1 $ 0.1 $ 0.1