Lease Commitments Lease Commitments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Lease Commitments [Abstract]
Operating Leases, Future Minimum Payments Due	$ 22.5
Operating Leases, Future Minimum Payments Due, Next Twelve Months	5.5
Operating Leases, Future Minimum Payments, Due in Two Years	4.4
Operating Leases, Future Minimum Payments, Due in Three Years	4.1
Operating Leases, Future Minimum Payments, Due in Four Years	3.8
Operating Leases, Future Minimum Payments, Due in Five Years	2.8
Operating Leases, Future Minimum Payments, Due Thereafter	1.9
Operating Leases, Rent Expense, Net	$ 8.2	$ 7.1	$ 6.3