Accumulated Other Comprehensive Loss (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, beginning balance	$ (1,837,713)	$ (1,703,214)
Other comprehensive income (loss)
Other comprehensive income (loss) before reclassifications	(130,944)	(142,841)
Amounts reclassified from accumulated other comprehensive income (loss)	9,814	8,342
Total other comprehensive income (loss)	(121,130)	(134,499)
Accumulated other comprehensive (loss) income, ending balance	(1,958,843)	(1,837,713)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, beginning balance	(1,866,388)	(1,726,994)
Other comprehensive income (loss)
Other comprehensive income (loss) before reclassifications	(114,552)	(139,394)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Total other comprehensive income (loss)	(114,552)	(139,394)
Accumulated other comprehensive (loss) income, ending balance	(1,980,940)	(1,866,388)
Net Unrealized Gains (Losses) On Marketable Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, beginning balance	0	(3,406)
Other comprehensive income (loss)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	0	3,406
Total other comprehensive income (loss)	0	3,406
Accumulated other comprehensive (loss) income, ending balance	0	0
Net Minimum Pension Liability
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, beginning balance	28,675	27,186
Other comprehensive income (loss)
Other comprehensive income (loss) before reclassifications	(16,392)	(3,447)
Amounts reclassified from accumulated other comprehensive income (loss)	(9,814)	4,936
Total other comprehensive income (loss)	(6,578)	1,489
Accumulated other comprehensive (loss) income, ending balance	$ 22,097	$ 28,675