Leases (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($) property	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) property	Jun. 30, 2018 USD ($)	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
Other Commitments [Line Items]
Operating lease right of use assets	$ 87.7		$ 87.7		$ 93.9	$ 0.0
Operating lease liability	$ 93.5		$ 93.5		$ 99.4
Number of Leased Properties Owned by Related Parties | property	2		2
Costs and Expenses, Related Party	$ 0.3		$ 0.6	$ 0.3
Lessee, Operating Lease, Leases Not Yet Commenced, Value	$ 4.5		$ 4.5
Lessee, Operating Lease, Leases Not yet Commenced, Term of Contract	6 years		6 years
Operating Leases, Rent Expense		$ 8.7		$ 15.6