Note 3 - Revenue Recognition - Revenue by Major Product Category (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Total Revenue	$ 40,467	$ 52,719
Percent of Revenue	100.00%	100.00%
Data Center [Member]
Total Revenue	$ 33,264	$ 38,499
Percent of Revenue	82.20%	73.00%
CATV [Member]
Total Revenue	$ 4,223	$ 11,962
Percent of Revenue	10.40%	22.70%
Telecom [Member]
Total Revenue	$ 2,560	$ 1,738
Percent of Revenue	6.30%	3.30%
FTTH [Member]
Total Revenue	$ 0	$ 94
Percent of Revenue	0.00%	0.20%
Product and Service, Other [Member]
Total Revenue	$ 420	$ 426
Percent of Revenue	1.00%	0.80%