Basis of Presentation Basis of Presentation (Details) - USD ($) $ in Millions	Mar. 31, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right-of-use assets	$ 112.7
Operating lease liabilities	$ 114.6
ASC 842
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right-of-use assets		$ 109.1
Operating lease liabilities		$ 110.4