Accounts Receivable (Details 1) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Allowance for Doubtful Accounts
Balance at Beginning of Year	$ 494,000	$ 403,000
Charged to Costs and Expenses	30,000	91,000
Deductions from Reserves
Balance at End of Year	$ 524,000	$ 494,000