Leases - Lease Cost (Details) $ in Millions	6 Months Ended
	Jun. 30, 2019 USD ($)
Leases [Abstract]
Amortization of Right-of-Use Assets	$ 0.3
Operating Lease Cost	11.2
Short-Term Lease Cost	0.1
Total Expense	11.6
Sublease Income	(0.1)
Total Lease Cost	$ 11.5