Leases - Lease Expense (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Leases [Abstract]
Amortization of right-of-use assets	$ 4.1
Interest on lease liabilities	3.5
Operating lease cost	36.5
Variable lease cost	2.9
Short-term lease cost	1.2
Net lease cost	$ 48.2