Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income before income taxes	$ 44.5	$ 41.4
Income tax provision	$ 13.4	$ 7.0
Effective tax rate	30.10%	16.90%
Federal statutory rate	21.00%
Unrecognized tax benefits	$ 181.6
Unrecognized tax benefits, if recognized, would affect the effective tax rate	178.2
Unrecognized tax benefits could decrease up to	$ 30.4

Amount of decrease reasonably possible in the next twelve months for the unrecognized tax benefit.

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