Revenue from Contracts with Customers (Details 1) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues	$ 17,544,338	$ 18,880,506	$ 37,623,957	$ 37,492,745
U.S. Federal Government [Member]
Revenues	13,574,338	14,975,815	27,848,384	28,719,163
U.S. State and Local Governments [Member]
Revenues	94,396	108,885	218,503	158,312
Foreign Governments [Member]
Revenues	79,295	50,910	106,366	96,452
Commercial Enterprises [Member]
Revenues	$ 3,796,309	$ 3,744,895	$ 9,450,704	$ 8,518,818