Income Taxes (Details Textual) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Decrease in Income Tax Expenses Unrecognized Tax Benefits if Recognized Net of Federal Tax			$ (315.9)
Tax Cuts and Jobs Act of 2017, change in tax rate, income tax expense (benefit)			371.4
Effective Income Tax Rate Reconciliation, Percent	25.00%	30.00%
Tax Cuts and Jobs Act of 2017, transition tax for accumulated roreign earnings, income tax expense (benefit)			$ 57.2