Accumulated Other Comprehensive Loss (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Other comprehensive income (loss)
Accumulated other comprehensive (loss) income, beginning balance			$ (21,224,797)
Total other comprehensive income (loss), net of applicable taxes:	$ 129,956	$ 5,433	44,712	$ (180,096)
Accumulated other comprehensive (loss) income, ending balance	(11,439,979)		(11,439,979)
Foreign Currency Translation
Other comprehensive income (loss)
Accumulated other comprehensive (loss) income, beginning balance	(2,066,185)	(2,051,917)	(1,980,940)	(1,866,388)
Other comprehensive income (loss) before reclassifications	129,956	5,433	44,711	(180,096)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Total other comprehensive income (loss), net of applicable taxes:	129,956	5,433	44,711	(180,096)
Accumulated other comprehensive (loss) income, ending balance	(1,936,229)	(2,046,484)	(1,936,229)	(2,046,484)
Net Unrealized Gains (Losses) on Marketable Securities
Other comprehensive income (loss)
Accumulated other comprehensive (loss) income, beginning balance	0	0	0	0
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Total other comprehensive income (loss), net of applicable taxes:	0	0	0	0
Accumulated other comprehensive (loss) income, ending balance	0	0	0	0
Net Minimum Pension Liability
Other comprehensive income (loss)
Accumulated other comprehensive (loss) income, beginning balance	22,097	28,675	22,097	28,675
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Total other comprehensive income (loss), net of applicable taxes:	0	0	0	0
Accumulated other comprehensive (loss) income, ending balance	22,097	28,675	22,097	28,675
Accumulated Other Comprehensive loss, net
Other comprehensive income (loss)
Accumulated other comprehensive (loss) income, beginning balance	(2,044,088)	(2,023,242)	(1,958,843)	(1,837,713)
Other comprehensive income (loss) before reclassifications	129,956	5,433	44,711	(180,096)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Total other comprehensive income (loss), net of applicable taxes:	129,956	5,433	44,711	(180,096)
Accumulated other comprehensive (loss) income, ending balance	$ (1,914,132)	$ (2,017,809)	$ (1,914,132)	$ (2,017,809)