Note R - Segment and Geographic Information (Details Textual) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number of Reportable Segments									1
Revenue from Contract with Customer, Excluding Assessed Tax, Total	$ 48,658	$ 46,084	$ 43,411	$ 52,719	$ 58,018	$ 56,386	$ 87,822	$ 65,239	$ 190,872	$ 267,465	$ 382,329
Percentage of Revenue									100.00%	100.00%	100.00%
Data Center [Member]
Revenue from Contract with Customer, Excluding Assessed Tax, Total									$ 143,563	$ 200,236	$ 306,712
Percentage of Revenue									75.20%	74.90%	80.20%
CATV [Member]
Revenue from Contract with Customer, Excluding Assessed Tax, Total									$ 37,328	$ 51,699	$ 60,756
Percentage of Revenue									19.60%	19.30%	15.90%
Telecom [Member]
Revenue from Contract with Customer, Excluding Assessed Tax, Total									$ 8,429	$ 13,159	$ 12,899
Percentage of Revenue									4.40%	4.90%	3.40%
FTTH [Member]
Revenue from Contract with Customer, Excluding Assessed Tax, Total									$ 190	$ 818	$ 490
Percentage of Revenue									0.10%	0.30%	0.10%