Leases Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Millions		Mar. 31, 2019	Jan. 01, 2019
Leases [Abstract]
2019	[1]	$ 3.4
2020		4.5
2021		4.4
2022		4.3
2023		3.8
Thereafter		2.1
Total		22.5
Less: discount		(2.6)
Total operating lease liabilities		$ 19.9	$ 20.8

[1] For the nine-month period beginning April 1, 2019.