Segment, Customer and Geographic Information - Assets by Segment (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Results of operations by segments
Accounts receivable	$ 18,347	$ 19,101
Inventories	12,692	14,442
Property and equipment, net	13,059	12,609
Goodwill	3,332	3,332
Intangible assets, net	2,985	3,275
Deferred tax assets, net	5,399	4,512
Other noncurrent assets	35	36
Operating Segments [Member] | Connected Solutions [Member]
Results of operations by segments
Accounts receivable	12,513	12,731
Inventories	10,834	12,301
Property and equipment, net	9,699	9,756
Goodwill	0	0
Intangible assets, net	195	233
Deferred tax assets, net	0	0
Other noncurrent assets	0	0
Operating Segments [Member] | RF Solutions [Member]
Results of operations by segments
Accounts receivable	5,834	6,370
Inventories	1,858	2,141
Property and equipment, net	2,016	2,122
Goodwill	3,332	3,332
Intangible assets, net	2,790	3,042
Deferred tax assets, net	0	0
Other noncurrent assets	0	0
Corporate, Non-Segment [Member]
Results of operations by segments
Accounts receivable	0	0
Inventories	0	0
Property and equipment, net	1,344	731
Goodwill	0	0
Intangible assets, net	0	0
Deferred tax assets, net	5,399	4,512
Other noncurrent assets	$ 35	$ 36