Income Taxes (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Income Tax Disclosure [Abstract]    
U.S Federal statutory rate 21.00%  
Income tax expense $ 26 $ 11
Pre-tax income $ 4,346 $ 671
Effective tax rate 0.60% 1.60%