Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 5,577	$ 5,571
Marketable securities	3,132	2,689
Receivables, net of allowance for doubtful accounts of $491 and $472, respectively	6,247	7,794
Inventories, net	14,622	14,415
Distributor channel inventories		1,555
Prepaid expenses and other assets	1,963	1,862
Total current assets	31,541	33,886
Long-term marketable securities	7,416	10,349
Long-term inventories, net	8,565	8,708
Property and equipment, net	1,481	1,549
Intangibles, net	7,640	6,543
Deferred income taxes	7,227	6,531
Other assets	316	311
Total assets	64,186	67,877
Current liabilities:
Accounts payable	4,295	4,122
Accrued liabilities	1,975	1,843
Deferred product revenue	282	4,635
Total current liabilities	6,552	10,600
Deferred rent	81	103
Other long-term liabilities	679	607
Total liabilities	7,312	11,310
Shareholders' equity:
Common stock, par value $0.001, 50,000,000 shares authorized, 8,301,273 and 8,319,022 shares issued and outstanding	8	8
Additional paid-in capital	47,612	47,464
Accumulated other comprehensive loss	(113)	(65)
Retained earnings	9,367	9,160
Total shareholders' equity	56,874	56,567
Total liabilities and shareholders' equity	$ 64,186	$ 67,877

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130549-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682