v3.26.1
Retirement Benefits (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 28, 2026
Jun. 29, 2025
Jun. 28, 2026
Jun. 29, 2025
Defined Benefit Plan Disclosure [Line Items]        
Total retirement benefit expense $ 4.3 $ 4.1 $ 8.6 $ 8.0
Pension Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost - benefits earned during the year 1.5 1.4 2.9 2.7
Interest cost on benefits earned in prior years 4.8 4.3 9.6 8.6
Expected return on plan assets (4.1) (3.9) (8.2) (7.9)
Amortization of prior service cost (credit) 0.1 0.1 0.2 0.2
Amortization of net actuarial loss 0.0 0.0 0.0 0.0
Total retirement benefit expense 2.3 1.9 4.5 3.6
Other Postretirement Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost - benefits earned during the year 0.1 0.1 0.2 0.2
Interest cost on benefits earned in prior years 2.3 2.5 4.5 4.9
Expected return on plan assets 0.0 0.0 0.0 0.0
Amortization of prior service cost (credit) (0.1) (0.2) (0.1) (0.4)
Amortization of net actuarial loss 1.3 1.3 2.6 2.6
Total retirement benefit expense $ 3.6 $ 3.7 $ 7.2 $ 7.3