Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue
Revenue	$ 56,386	$ 88,879	$ 209,447	$ 302,474
Percentage of Revenue	100.00%		100.00%
Data Center
Disaggregation of Revenue
Revenue	$ 38,954		$ 158,577
Percentage of Revenue	69.10%		75.70%
CATV
Disaggregation of Revenue
Revenue	$ 14,295		$ 39,047
Percentage of Revenue	25.40%		18.60%
Telecom
Disaggregation of Revenue
Revenue	$ 2,656		$ 10,399
Percentage of Revenue	4.70%		5.00%
FTTH
Disaggregation of Revenue
Revenue	$ 221		$ 498
Percentage of Revenue	0.40%		0.20%
Other
Disaggregation of Revenue
Revenue	$ 260		$ 926
Percentage of Revenue	0.50%		0.40%
Before Topic 606
Disaggregation of Revenue
Revenue		$ 88,879		$ 302,474
Percentage of Revenue		100.00%		100.00%
Before Topic 606 | Data Center
Disaggregation of Revenue
Revenue		$ 65,819		$ 244,711
Percentage of Revenue		74.10%		80.90%
Before Topic 606 | CATV
Disaggregation of Revenue
Revenue		$ 18,932		$ 46,430
Percentage of Revenue		21.30%		15.40%
Before Topic 606 | Telecom
Disaggregation of Revenue
Revenue		$ 3,474		$ 9,722
Percentage of Revenue		3.90%		3.20%
Before Topic 606 | FTTH
Disaggregation of Revenue
Revenue		$ 182		$ 405
Percentage of Revenue		0.20%		0.10%
Before Topic 606 | Other
Disaggregation of Revenue
Revenue		$ 472		$ 1,206
Percentage of Revenue		0.50%		0.40%