Income Taxes (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2018
Income Taxes [Line Items]
Tax Adjustments, Settlements, and Unusual Provisions	$ 94.4	$ 39.6
Undistributed Earnings of Foreign Subsidiaries		$ 1,000.0
Restricted Cash			$ 37.6
Transition [Member]
Income Taxes [Line Items]
Tax Adjustments, Settlements, and Unusual Provisions	66.5
remeasurement new tax rate [Member]
Income Taxes [Line Items]
Tax Adjustments, Settlements, and Unusual Provisions	12.8
State and Foreign on undistributed foreign earnings [Member]
Income Taxes [Line Items]
Tax Adjustments, Settlements, and Unusual Provisions	$ 15.1