Leases - Components of Lease Expense (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Lease Cost
Interest expense on lease liabilities	$ 0.1	$ 0.1
Amortization of right-of-use assets	0.1	0.2
Operating Lease, Cost	1.6	3.1
Short-term Lease, Cost	0.1	0.2
Lease, Cost	$ 1.9	$ 3.6