Consolidated Statements of Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 1,052,401	$ (10,998,794)
Other comprehensive income (loss), net of applicable taxes:
Foreign currency translation	(114,552)	(139,394)
Net unrealized gain (loss) on marketable securities	0	3,406
Net minimum pension liability	(6,578)	1,489
Total other comprehensive loss, net of applicable taxes:	(121,130)	(134,499)
Total comprehensive income (loss)	931,271	(11,133,293)
Less: Accrual of Series A redeemable convertible preferred stock dividends	873,043	777,890
Less: Accretion to redemption value of Series A redeemable convertible preferred stock	0	1,181,446
Total comprehensive income (loss) attributable to common stockholders	$ 58,228	$ (13,092,629)