Income Taxes (Details) - USD ($)	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Reduction to tax expense	$ 1,522,000
Effective tax rate		19.60%	21.10%	69.60%
Effective tax rate scenario without TCJA				20.20%
TCJA one-time expense				$ 99,214,000
TCJA, benefit on current year repatriation				2,514,000
TCJA liability recorded for earnings expected to repatriate				$ 6,932