Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Schedule of operations by geographic segment
Intercompany sales	$ 1,295	$ 1,798	$ 4,669	$ 9,479
Net sales	40,216	38,822	123,340	97,569
Segment net income (loss)	1,386	1,745	4,898	823
Depreciation and amortization	1,525	1,632	4,301	3,377
Total assets	181,027	134,101	181,027	134,101	137,568
Subtotal [Member]
Schedule of operations by geographic segment
Subtotal	41,511	40,620	128,009	107,048
Eliminations [Member]
Schedule of operations by geographic segment
Intercompany sales	(1,295)	(1,798)	(4,669)	(9,479)
Mobile communication [Member] | United States [Member]
Schedule of operations by geographic segment
Subtotal	21,569	16,609	59,243	47,202
Mobile communication [Member] | Canada [Member]
Schedule of operations by geographic segment
Subtotal	108	205	391	571
Mobile communication [Member] | Europe [Member]
Schedule of operations by geographic segment
Subtotal	4,803	2,955	13,312	12,804
Mobile communication [Member] | Other geographic areas [Member]
Schedule of operations by geographic segment
Subtotal	2,533	2,435	6,226	6,502
Guidance and stabilization [Member] | United States [Member]
Schedule of operations by geographic segment
Subtotal	2,026	1,720	4,889	4,848
Guidance and stabilization [Member] | Canada [Member]
Schedule of operations by geographic segment
Subtotal	3,700	2,718	11,583	7,925
Guidance and stabilization [Member] | Europe [Member]
Schedule of operations by geographic segment
Subtotal	1,437	3,407	5,895	7,758
Guidance and stabilization [Member] | Other geographic areas [Member]
Schedule of operations by geographic segment
Subtotal	4,040	8,773	21,801	9,959
Americas [Member]
Schedule of operations by geographic segment
Intercompany sales	746	1,577	3,286	8,208
Net sales	33,763	34,801	106,301	81,382
Segment net income (loss)	1,687	1,996	5,302	1,621
Depreciation and amortization	1,117	1,118	3,391	3,021
Total assets	132,415	114,039	132,415	114,039
Americas [Member] | Subtotal [Member]
Schedule of operations by geographic segment
Subtotal	34,509	36,378	109,587	89,590
Americas [Member] | Eliminations [Member]
Schedule of operations by geographic segment
Intercompany sales	(746)	(1,577)	(3,286)	(8,208)
Americas [Member] | Mobile communication [Member] | United States [Member]
Schedule of operations by geographic segment
Subtotal	21,270	16,609	58,767	47,202
Americas [Member] | Mobile communication [Member] | Canada [Member]
Schedule of operations by geographic segment
Subtotal	108	205	391	571
Americas [Member] | Mobile communication [Member] | Europe [Member]
Schedule of operations by geographic segment
Subtotal	181	99	409	342
Americas [Member] | Mobile communication [Member] | Other geographic areas [Member]
Schedule of operations by geographic segment
Subtotal	1,001	1,270	2,566	2,777
Americas [Member] | Guidance and stabilization [Member] | United States [Member]
Schedule of operations by geographic segment
Subtotal	2,026	1,720	4,889	4,848
Americas [Member] | Guidance and stabilization [Member] | Canada [Member]
Schedule of operations by geographic segment
Subtotal	3,700	2,718	11,583	7,925
Americas [Member] | Guidance and stabilization [Member] | Europe [Member]
Schedule of operations by geographic segment
Subtotal	1,437	3,407	5,895	7,758
Americas [Member] | Guidance and stabilization [Member] | Other geographic areas [Member]
Schedule of operations by geographic segment
Subtotal	4,040	8,773	21,801	9,959
Europe and Asia [Member]
Schedule of operations by geographic segment
Intercompany sales	549	221	1,383	1,271
Net sales	6,453	4,021	17,039	16,187
Segment net income (loss)	(301)	(251)	(404)	(798)
Depreciation and amortization	408	514	910	356
Total assets	48,612	20,062	48,612	20,062
Europe and Asia [Member] | Subtotal [Member]
Schedule of operations by geographic segment
Subtotal	7,002	4,242	18,422	17,458
Europe and Asia [Member] | Eliminations [Member]
Schedule of operations by geographic segment
Intercompany sales	(549)	(221)	(1,383)	(1,271)
Europe and Asia [Member] | Mobile communication [Member] | United States [Member]
Schedule of operations by geographic segment
Subtotal	299	0	476	0
Europe and Asia [Member] | Mobile communication [Member] | Canada [Member]
Schedule of operations by geographic segment
Subtotal	0	0	0	0
Europe and Asia [Member] | Mobile communication [Member] | Europe [Member]
Schedule of operations by geographic segment
Subtotal	4,622	2,856	12,903	12,462
Europe and Asia [Member] | Mobile communication [Member] | Other geographic areas [Member]
Schedule of operations by geographic segment
Subtotal	1,532	1,165	3,660	3,725
Europe and Asia [Member] | Guidance and stabilization [Member] | United States [Member]
Schedule of operations by geographic segment
Subtotal	0	0	0	0
Europe and Asia [Member] | Guidance and stabilization [Member] | Canada [Member]
Schedule of operations by geographic segment
Subtotal	0	0	0	0
Europe and Asia [Member] | Guidance and stabilization [Member] | Europe [Member]
Schedule of operations by geographic segment
Subtotal	0	0	0	0
Europe and Asia [Member] | Guidance and stabilization [Member] | Other geographic areas [Member]
Schedule of operations by geographic segment
Subtotal	$ 0	$ 0	$ 0	$ 0