Accounts Receivable (Tables)

12 Months Ended

Dec. 31, 2017

Receivables [Abstract]

Schedule of Accounts, Notes, Loans and Financing Receivable [Text Block]

Accounts receivable, net, consists of the following at December 31:

	2017			2016
Accounts receivable	$	8,227,383		$	6,798,943
Allowances for doubtful accounts	(56,291		)	(52,256		)
Accounts receivable, net	$	8,171,092		$	6,746,687

The company maintains allowances for doubtful accounts for estimated losses resulting from the inability of its customers to make required payments.  The allowances for doubtful accounts are determined using a combination of factors, including the length of time the receivables are outstanding, the current business environment, and historical experience. The company also has notes receivables with certain customers.  As of December 31, 2017,  the company has one customer with a combined gross note and accounts receivable balance of approximately $24,600.  The customer became delinquent on its repayment of the note during the fourth quarter of 2016. The company believes that it has adequately reserved for potential losses; however, it is possible that it could incur a loss in excess of the reserve.