Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2017
Income Taxes [Abstract]
Effective income tax rate	23.00%		34.10%
Increase in liability for uncertain tax positions	$ 32
Federal corporate tax rate	21.00%			35.00%
Provision of income tax expense (benefit)		$ (1,056)
Income tax expense (benefit)		(1,548)
Transition tax		$ 492
Estimated annualized tax addition for GILTI	$ 2,081
Income tax expense for GILTI	127
Estimated annualized tax deduction for FDII	(3,345)
Reduction in income tax expense for FDII	$ (203)
Reduction in income tax expense for DPAD			$ (447)