Segment, Customer and Geographic Information - Continuing Operations - Assets by Segment (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Results of operations by segments
Accounts receivable	$ 18,530	$ 19,101
Inventories	12,828	14,442
Current assets held for sale	0	50
Property and equipment, net	12,227	11,833
Goodwill	3,332	3,332
Intangible assets, net	2,403	3,275
Deferred tax assets, net	5,344	4,512
Other noncurrent assets	69	36
Non-current assets held for sale	0	776
Operating Segments [Member] | Connected Solutions [Member]
Results of operations by segments
Accounts receivable	13,243	12,731
Inventories	11,267	12,301
Current assets held for sale	0	0
Property and equipment, net	9,905	9,756
Goodwill	0	0
Intangible assets, net	116	233
Deferred tax assets, net	0	0
Other noncurrent assets	0	0
Non-current assets held for sale		0
Operating Segments [Member] | RF Solutions [Member]
Results of operations by segments
Accounts receivable	5,287	6,370
Inventories	1,561	2,141
Current assets held for sale	0	50
Property and equipment, net	1,395	1,346
Goodwill	3,332	3,332
Intangible assets, net	2,287	3,042
Deferred tax assets, net	0	0
Other noncurrent assets	0	0
Non-current assets held for sale		776
Corporate, Non-Segment [Member]
Results of operations by segments
Accounts receivable	0	0
Inventories	0	0
Current assets held for sale	0	0
Property and equipment, net	927	731
Goodwill	0	0
Intangible assets, net	0	0
Deferred tax assets, net	5,344	4,512
Other noncurrent assets	$ 69	36
Non-current assets held for sale		$ 0