Leases - Supplemental balance sheet information related to leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Operating lease assets, net	$ 52.4	$ 49.1
Total lease assets	106.6	108.4
Current lease liabilities	17.4	16.2
Finance lease liabilities	0.8	0.7
Noncurrent operating lease liabilities	36.2	34.7
Finance lease liabilities	101.6	102.4
Total lease liabilities	156.0	154.0
Operating lease amortization	35.5	29.4
Accrued interest	$ 0.2	$ 0.2
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, plant and equipment, net	Property, plant and equipment, net	Property, plant and equipment, net
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Notes payable and current maturities of long-term debt	Notes payable and current maturities of long-term debt	Notes payable and current maturities of long-term debt
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long-term debt including finance lease obligations	Long-term debt including finance lease obligations	Long-term debt including finance lease obligations
Property, plant, and equipment, net
Lessee, Lease, Description [Line Items]
Finance lease assets, net	$ 53.9	$ 58.5
Finance lease assets	69.6	65.8
Other assets, net
Lessee, Lease, Description [Line Items]
Finance lease assets, net	0.3	0.8
Finance lease assets	$ 1.3	$ 0.8