Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 601	$ 963
Investments	7,750	7,756
Trade receivables, less allowance for doubtful accounts of $11	855	902
Inventories	1,579	1,552
Other current assets	171	141
Income tax receivable	118	45
Total current assets	11,074	11,359
Deferred income tax asset, net	163	182
Intangible assets, net	741	800
Property and equipment, net	1,058	1,074
Total assets	13,036	13,415
Current liabilities
Contingent earn-out	0	150
Accounts payable	128	178
Accrued expenses	400	380
Total current liabilities	528	708
Commitments and contingencies
Stockholders' equity
Common stock par value $0.10 per share; authorized 10,000,000 shares; 3,395,521 shares issued and outstanding	339	339
Additional paid-in capital	2,008	2,004
Retained earnings	10,143	10,352
Accumulated other comprehensive gain (unrealized gain on available-for-sale securities, net of income tax)	18	12
Total stockholders' equity	12,508	12,707
Total liabilities and stockholders' equity	$ 13,036	$ 13,415

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Name:	us-gaap_AccountsPayableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.