Other assets - Schedule of Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]
2026	$ 4.8
2027	3.1
2028	2.5
2029	2.1
2030	1.7
2031 and thereafter	14.6
Total remaining lease payments	28.8
Less imputed interest	8.9
Total lease obligations	19.9
Less current obligations	$ 4.2	$ 3.5
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued liabilities	Accrued liabilities
Operating lease liabilities	$ 15.7	$ 17.1
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other liabilities	Other liabilities