Note N - Accumulated Other Comprehensive Income (Loss) - Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Losses on available-for-sale marketable securities		$ 403	$ 418	$ 799	$ 834
Provision for income taxes		(2)	113	(211)	(35)
Net income		(288)	(586)	(2,041)	(3,452)
Research and development, net	[1]	8,891	9,161	17,889	18,351
Sales and marketing	[2]	3,761	3,430	7,829	7,005
General and administrative	[3]	2,669	$ 2,372	5,250	$ 4,859
Reclassification out of Accumulated Other Comprehensive Income [Member]
Net income		52		56
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Losses on available-for-sale marketable securities		38		37
Provision for income taxes
Net income		38		37
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Provision for income taxes
Net income		9		9
Research and development, net		7		7
Sales and marketing		1		1
General and administrative		1		1
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Provision for income taxes
Net income		5		10
Research and development, net		3		7
Sales and marketing		2		3
General and administrative		$ 5		$ 10

[1] Includes equity-based compensation expense in the amount of $701 and $623 for the three months ended June 30, 2018 and 2017, respectively; and $1,353 and $1,239 for the six months ended June 30, 2018 and 2017, respectively.

[2] Includes equity-based compensation expense in the amount of $265 and $297 for the three months ended June 30, 2018 and 2017, respectively; and $671 and $597 for the six months ended June 30, 2018 and 2017, respectively.

[3] Includes equity-based compensation expense in the amount of $586 and $543 for the three months ended June 30, 2018 and 2017, respectively; and $1,129 and $1,061 for the six months ended June 30, 2018 and 2017, respectively.