Note 4 - Marketable Securities

9 Months Ended

Sep. 30, 2019

Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]

Marketable Securities

The Company has classified its marketable securities as available-for-sale securities. These securities are carried at estimated fair value with unrealized holding gains and losses included in accumulated other comprehensive income (loss) in stockholders’ equity until realized. Gains and losses on marketable security transactions are reported on the specific-identification method. Dividend and interest income are recognized when earned.

The amortized cost, gross unrealized holding gains, gross unrealized holding losses, and fair value for available-for-sale securities by major security type and class of securities at

September 30, 2019

and

December 31, 2018

were as follows:

	Amortized cost		Gross unrealized holding gains		Gross unrealized holding losses			Estimated fair value
September 30, 2019
Available-for-sale securities:
Corporate bonds and notes	$	2,331	$	25	$	(4	)	$	2,352
Municipal bonds		1,520		11		—			1,531
Total available-for-sale securities	$	3,851	$	36	$	(4	)	$	3,883

December 31, 2018
Available-for-sale securities:
Corporate bonds and notes	$	2,911	$	1	$	(31	)	$	2,881
Municipal bonds		1,849		—		(15	)		1,834
Total available-for-sale securities	$	4,760	$	1	$	(46	)	$	4,715

Maturities of marketable securities classified as available-for-sale securities were as follows at

September 30, 2019:

	Amortized cost		Estimated fair value
Due within one year	$	1,639	$	1,640
Due after one year through five years		2,212		2,243
Due after five years		—		—
Total available-for-sale securities	$	3,851	$	3,883

Debt securities in an unrealized loss position as of

September 30, 2019

were

not

deemed impaired at acquisition and subsequent declines in fair value are

not

deemed attributed to declines in credit quality. Management believes that it is more likely than

not

that the securities will receive a full recovery of par value, although there can be

assurance that such recovery will occur. The available-for-sale marketable securities with continuous gross unrealized loss position for less than

months and

months or greater and their related fair values were as follows:

	Less than 12 months					More than 12 months				Total
	Estimated fair value		Gross unrealized holding losses			Estimated fair value		Gross unrealized holding losses		Estimated fair value		Gross unrealized holding losses
As of September 30, 2019
Corporate bonds and notes	$	293	$	(4	)	$	101	$	—	$	394	$	(4	)
Municipal bonds		—		—			—		—		—		—
Total	$	293	$	(4	)	$	101	$	—	$	394	$	(4	)