Leases - Schedule of operating lease liabilities (Details) $ in Millions	Mar. 31, 2020 USD ($)
Operating Leases Liabilities
2020	$ 100.3
2021	106.1
2022	85.6
2023	58.2
2024	39.3
After 2024	97.3
Total lease payments	486.8
Less: Imputed interest	72.6
Present value of lease liabilities	$ 414.2
Weighted-average remaining lease term (years)	5 years 6 months
Weighted-average discount rate	4.90%
Finance Leases Liabilities
2020	$ 3.3
2021	4.4
2022	3.9
2023	2.9
2024	1.8
After 2024	6.2
Total lease payments	22.5
Less: Imputed interest	2.4
Present value of lease liabilities	$ 20.1
Weighted-average remaining lease term (years)	6 years 6 months
Weighted-average discount rate	4.80%
Total
2020	$ 103.6
2021	110.5
2022	89.5
2023	61.1
2024	41.1
After 2024	103.5
Total lease payments	509.3
Less: Imputed interest	75.0
Present value of lease liabilities	$ 434.3