Leases Leases - Supplemental balance sheet (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating lease assets	$ 270.3	$ 0.0
Finance lease assets	162.5	124.0
Total lease assets	432.8
Current liabilities operating leases	65.9	0.0
Current liabilities financing leases	32.5
Lease liabilities	218.4	$ 0.0
Noncurrent liabilities financing leases	117.0
Total lease liabilities	$ 433.8