Income Taxes (Details Textuals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Taxes (Textuals) [Line Items]
U.S. Tax Act Discrete Tax Benefit		$ 24
Effective tax rate	(19.40%)	10.60%
Reduction in Effective Tax Rate	22.20%
Tax Year 2018 [Member]
Income Taxes (Textuals) [Line Items]
U.S. statutory federal income tax rate	21.00%	35.00%
Internal Revenue Service (IRS) [Member] | Earliest Year [Member]
Income Tax Contingency [Line Items]
Open tax years by major tax jurisdiction	2008
Internal Revenue Service (IRS) [Member] | Latest Year [Member]
Income Tax Contingency [Line Items]
Open tax years by major tax jurisdiction	2014