Leases - Lease Costs (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 8.1
Finance Lease, Cost [Abstract]
Amortization of right-of-use assets	0.5
Interest on lease liabilities	0.2
Total finance lease cost	0.7
Variable lease cost	2.3
Total lease cost	$ 11.1