Income Taxes - US Statutory Rate Reconciliation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal income taxes at 34% statutory rate	$ 2,322,741	$ 2,496,270
State and local taxes, net of federal income tax effect	39,783	18,998
Permanent items	(370,978)	(25,077)
Transition tax on deemed repatriation of foreign earnings	1,169,263
Effect of federal rate change on deferred taxes	74,462
Foreign tax rate difference	(699,047)	(919,038)
Change in deferred income tax valuation allowance	(95,406)	74,552
Provision for income taxes	$ 2,440,818	$ 1,645,705