Leases and commitments - Maturities of Lease Liabilities, Topic 842 (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Finance Leases
2022	$ 1.6
2023	0.7
2024	0.5
2025	0.0
2026	0.0
Thereafter	0.0
Total lease payments	2.8
Less imputed interest	0.1
Total	2.7	$ 5.5
Operating Leases
2022	39.2
2023	25.6
2024	15.8
2025	6.1
2026	2.0
Thereafter	0.0
Total lease payments	88.7
Less imputed interest	7.2
Total	$ 81.5	$ 99.5