Basis of Presentation and Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Treasury Stock, Value, Acquired, Cost Method	$ 3.3	$ 182.6
Right of use asset	43.4	43.4
Lease liability	$ 48.6	$ 48.6
Accounting Standards Update 2016-19
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of use asset			$ 44.2
Lease liability			$ 49.9