Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Income Taxes [Abstract]
Foreign subsidiaries tax payable period	8 years
U.S. federal corporate tax rate	21.00%		35.00%
Change in tax rate, income tax benefit			$ (89.6)
Benefit relating to the reduction of the ASC 740-30 liability			69.0
Recorded provisional transition tax obligation			63.3
Adjustment of additional tax expense			7.9
Impact of transition tax expense after adjustments			$ 71.3
Income (loss) before income taxes	$ 65.8	$ (8.6)
Provision (benefit) for income taxes	$ 23.4	$ (1.6)
Effective income tax benefit rate	35.60%	18.90%
Increase in effective tax rate	12.00%