Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax expense (benefit)	$ 2.2	$ 6.9
Effective tax rate	3.60%	24.80%
Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax expense (benefit)	$ (15.9)