Accumulated Other Comprehensive Loss (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Other comprehensive (loss) income
Accumulated other comprehensive (loss) income, beginning balance			$ (21,702,577)
Total other comprehensive income (loss), net of applicable taxes:	$ 5,433	$ (333,766)	(180,096)	$ (553,966)
Accumulated other comprehensive (loss) income, ending balance	(23,537,476)		(23,537,476)
Foreign Currency Translation
Other comprehensive (loss) income
Accumulated other comprehensive (loss) income, beginning balance	(2,051,917)	(1,954,409)	(1,866,388)	(1,726,994)
Other comprehensive (loss) income before reclassifications	5,433	(334,161)	(180,096)	(561,576)
Amounts reclassified from accumulated other comprehensive (loss) income	0	0	0	0
Total other comprehensive income (loss), net of applicable taxes:	5,433	(334,161)	(180,096)	(561,576)
Accumulated other comprehensive (loss) income, ending balance	(2,046,484)	(2,288,570)	(2,046,484)	(2,288,570)
Net Unrealized Gains (Losses) on Marketable Securities
Other comprehensive (loss) income
Accumulated other comprehensive (loss) income, beginning balance	0	633	0	(3,406)
Other comprehensive (loss) income before reclassifications	0	(81)	0	2,513
Amounts reclassified from accumulated other comprehensive (loss) income	0	(202)	0	1,243
Total other comprehensive income (loss), net of applicable taxes:	0	(283)	0	3,756
Accumulated other comprehensive (loss) income, ending balance	0	350	0	350
Net Minimum Pension Liability
Other comprehensive (loss) income
Accumulated other comprehensive (loss) income, beginning balance	28,675	30,362	28,675	27,186
Other comprehensive (loss) income before reclassifications	0	(550)	0	1,423
Amounts reclassified from accumulated other comprehensive (loss) income	0	1,228	0	2,431
Total other comprehensive income (loss), net of applicable taxes:	0	678	0	3,854
Accumulated other comprehensive (loss) income, ending balance	28,675	31,040	28,675	31,040
Accumulated Other Comprehensive loss, net
Other comprehensive (loss) income
Accumulated other comprehensive (loss) income, beginning balance	(2,023,242)	(1,923,414)	(1,837,713)	(1,703,214)
Other comprehensive (loss) income before reclassifications	5,433	(334,792)	(180,096)	(557,640)
Amounts reclassified from accumulated other comprehensive (loss) income	0	1,026	0	3,674
Total other comprehensive income (loss), net of applicable taxes:	5,433	(333,766)	(180,096)	(553,966)
Accumulated other comprehensive (loss) income, ending balance	$ (2,017,809)	$ (2,257,180)	$ (2,017,809)	$ (2,257,180)