Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Income Tax Contingency [Line Items]
Unrecognized tax benefit more likely than not percentage threshold	50.00%
Unrecognized Tax Benefits	$ 55.7
Unrecognized tax benefits that would impact effective tax rate	47.5
Decrease in Unrecognized Tax Benefits is Reasonably Possible	20.0
Interest expense or penalties, uncertain tax positions	0.4	$ 0.3
Accrued interest, uncertain tax positions	$ 3.1		$ 2.7
Internal Revenue Service (IRS) [Member]
Income Tax Contingency [Line Items]
Earliest year subject to examination	2000