Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 4,584	$ 6,121	$ 6,678
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,063	2,807	2,294
Deferred income taxes	(288)	(1,450)	168
Loss on disposal of equipment	6
Non-cash interest income	(41)
Stock compensation expense	594	582	671
Changes in operating assets and liabilities:
Accounts receivable	(355)	1,316	(2,298)
Other current assets	145	(133)	822
Accounts payable	77	(990)	144
Accrued expenses	144	893	790
Net cash provided by operating activities	7,929	9,146	9,269
Cash flows from investing activities:
Purchases of investments in marketable securities	(4,035)
Increase in long-term assets; capitalized patent costs	(133)	(49)	(82)
Purchases of property and equipment and capitalized software development costs	(1,191)	(1,197)	(2,012)
Net cash used in investing activities	(5,359)	(1,246)	(2,094)
Cash flows from financing activities:
Dividends paid	(3,797)	(3,289)	(3,267)
Proceeds from stock options and tax withholding related to vested shares from employee stock plans	(93)	(163)	(149)
Proceeds from equipment financing		2,078	610
Payments of equipment financing	(1,749)	(2,082)	(3,120)
Net cash used in financing activities	(5,639)	(3,456)	(5,926)
Effect of exchange rate changes on cash and cash equivalents	(1,027)	(217)
Net increase (decrease) in cash and cash equivalents	(4,096)	4,227	1,249
Cash and cash equivalents, beginning of year	8,165	3,938	2,689
Cash and cash equivalents, end of year	4,069	8,165	3,938
Supplemental disclosures of cash flow information:
Cash paid for income taxes	3,743	2,824	1,814
Cash paid for interest	108	70	134
Non-cash investing and financing activities	(41)
Purchases of equipment through accounts payable and accrued liabilities	$ 207	$ 25	$ 472