Note N - Accumulated Other Comprehensive Income (Loss) - Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Gains on available-for-sale marketable securities		$ 492	$ 382	$ 1,291	$ 1,216
Provision for income taxes		350	54	139	19
Net income		405	578	(1,637)	(2,874)
Research and development, net	[1]	9,614	9,214	27,503	27,565
Sales and marketing	[2]	3,640	3,635	11,468	10,640
General and administrative	[3]	2,362	2,483	7,612	7,342
Net income		755	$ 632	(1,498)	$ (2,855)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Gains on available-for-sale marketable securities		(1)
Net income		11		67
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Gains on available-for-sale marketable securities				36
Provision for income taxes
Net income		(1)		36
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Provision for income taxes
Net income		7		6
Research and development, net		5		13
Sales and marketing		1		1
General and administrative		1		2
Net income		7		16
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Provision for income taxes
Net income		5		15
Research and development, net		3		10
Sales and marketing		2		5
General and administrative		$ 5		$ 15

[1] Includes equity-based compensation expense in the amount of $781 and $576 for the three months ended September 30, 2018 and 2017, respectively; and $2,134 and $1,815 for the nine months ended September 30, 2018 and 2017, respectively.

[2] Includes equity-based compensation expense in the amount of $283 and $273 for the three months ended September 30, 2018 and 2017, respectively; and $954 and $870 for the nine months ended September 30, 2018 and 2017, respectively.

[3] Includes equity-based compensation expense in the amount of $574 and $505 for the three months ended September 30, 2018 and 2017, respectively; and $1,703 and $1,566 for the nine months ended September 30, 2018 and 2017, respectively.