v3.26.1
BENEFIT PLANS: (Details) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Post retirement defined benefit plans    
Defined benefit plan, net periodic benefit costs    
Service cost $ 1.6 $ 1.2
Interest cost 2.0 1.9
Expected return on plan assets (4.7) (3.6)
Amortization of prior service cost/ (credit) 0.1 0.1
Amortization of net loss/(gain) (0.6) 0.1
Net periodic (benefit) cost (1.6) (0.3)
Post-retirement health care plans    
Defined benefit plan, net periodic benefit costs    
Interest cost 1.2 1.0
Net periodic (benefit) cost $ 1.2 $ 1.0