Leases - Assets and Lease Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Assets
Operating lease assets	$ 147.0	$ 144.8
Liabilities
Operating lease liabilities	35.9	35.8
Operating lease liabilities	136.0	138.7
Total lease liabilities	$ 171.9	$ 174.5