Costs and Estimated Earnings on Uncompleted Contracts (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Contractors [Abstract]
Costs incurred on uncompleted contracts	$ 48,681,608	$ 47,282,570
Estimated earnings	16,076,125	18,644,216
Total estimated contract revenue	64,757,733	65,926,786
Less billings to date	58,849,655	59,458,744
Total	5,908,078	6,468,042
Costs and estimated earnings in excess of billings on uncompleted contracts	6,074,346	7,313,099
Billings in excess of costs and estimated earnings on uncompleted contracts	(166,268)	(845,057)
Contract receivable	$ 3,300,000	$ 3,200,000