Interim Financial Reporting (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Deferred Revenue Arrangement [Line Items]
Contract retentions	$ 1,121,000	$ 1,065,000
Allowance for doubtful accounts	$ 279,000	$ 194,000
Licensing contract term	5 years
Minimum
Deferred Revenue Arrangement [Line Items]
Royalty percent earned on licensing agreement	4.00%
Maximum
Deferred Revenue Arrangement [Line Items]
Royalty percent earned on licensing agreement	6.00%