Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								9 Months Ended	12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Intercompany sales										$ 5,649	$ 10,549	$ 8,877
Net sales										162,288	137,112	112,536
Segment net income (loss)	(365)	1,386	1,549	1,963	2,757	1,745	453	(1,375)	4,533	4,533	3,580	860
Depreciation and amortization										5,994	4,610	4,374
Total assets	183,849				137,568					183,849	137,568	128,556
Subtotal [Member]
Segment Reporting Information [Line Items]
Subtotal										167,937	147,661	121,413
Eliminations [Member]
Segment Reporting Information [Line Items]
Intercompany sales										(5,649)	(10,549)	(8,877)
Mobile communication [Member] | United States [Member]
Segment Reporting Information [Line Items]
Subtotal										79,828	62,857	50,797
Mobile communication [Member] | Canada [Member]
Segment Reporting Information [Line Items]
Subtotal										501	777	875
Mobile communication [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Subtotal										19,026	15,672	13,682
Mobile communication [Member] | Other geographic areas [Member]
Segment Reporting Information [Line Items]
Subtotal										8,796	8,379	4,848
Guidance and stabilization [Member] | United States [Member]
Segment Reporting Information [Line Items]
Subtotal										7,892	8,632	11,951
Guidance and stabilization [Member] | Canada [Member]
Segment Reporting Information [Line Items]
Subtotal										13,810	10,736	16,643
Guidance and stabilization [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Subtotal										7,421	11,793	7,877
Guidance and stabilization [Member] | Other geographic areas [Member]
Segment Reporting Information [Line Items]
Subtotal										25,014	18,266	5,863
Americas [Member]
Segment Reporting Information [Line Items]
Intercompany sales										3,465	8,485	7,793
Net sales										137,379	117,414	95,724
Segment net income (loss)										5,260	4,316	396
Depreciation and amortization										4,521	4,116	3,948
Total assets	136,051				118,076					136,051	118,076	112,557
Americas [Member] | Subtotal [Member]
Segment Reporting Information [Line Items]
Subtotal										140,844	125,899	103,517
Americas [Member] | Eliminations [Member]
Segment Reporting Information [Line Items]
Intercompany sales										(3,465)	(8,485)	(7,793)
Americas [Member] | Mobile communication [Member] | United States [Member]
Segment Reporting Information [Line Items]
Subtotal										78,729	62,857	50,797
Americas [Member] | Mobile communication [Member] | Canada [Member]
Segment Reporting Information [Line Items]
Subtotal										462	777	875
Americas [Member] | Mobile communication [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Subtotal										455	417	438
Americas [Member] | Mobile communication [Member] | Other geographic areas [Member]
Segment Reporting Information [Line Items]
Subtotal										3,596	3,936	1,280
Americas [Member] | Guidance and stabilization [Member] | United States [Member]
Segment Reporting Information [Line Items]
Subtotal										7,892	8,632	11,951
Americas [Member] | Guidance and stabilization [Member] | Canada [Member]
Segment Reporting Information [Line Items]
Subtotal										13,810	10,736	16,643
Americas [Member] | Guidance and stabilization [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Subtotal										7,421	11,793	7,877
Americas [Member] | Guidance and stabilization [Member] | Other geographic areas [Member]
Segment Reporting Information [Line Items]
Subtotal										25,014	18,266	5,863
Europe and Asia [Member]
Segment Reporting Information [Line Items]
Intercompany sales										2,184	2,064	1,084
Net sales										24,909	19,698	16,812
Segment net income (loss)										(727)	(736)	464
Depreciation and amortization										1,473	494	426
Total assets	47,798				19,492					47,798	19,492	15,999
Europe and Asia [Member] | Subtotal [Member]
Segment Reporting Information [Line Items]
Subtotal										27,093	21,762	17,896
Europe and Asia [Member] | Eliminations [Member]
Segment Reporting Information [Line Items]
Intercompany sales										(2,184)	(2,064)	(1,084)
Europe and Asia [Member] | Mobile communication [Member] | United States [Member]
Segment Reporting Information [Line Items]
Subtotal										1,099	0	0
Europe and Asia [Member] | Mobile communication [Member] | Canada [Member]
Segment Reporting Information [Line Items]
Subtotal										39	0	0
Europe and Asia [Member] | Mobile communication [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Subtotal										18,571	15,255	13,244
Europe and Asia [Member] | Mobile communication [Member] | Other geographic areas [Member]
Segment Reporting Information [Line Items]
Subtotal										5,200	4,443	3,568
Europe and Asia [Member] | Guidance and stabilization [Member] | United States [Member]
Segment Reporting Information [Line Items]
Subtotal										0	0	0
Europe and Asia [Member] | Guidance and stabilization [Member] | Canada [Member]
Segment Reporting Information [Line Items]
Subtotal										0	0	0
Europe and Asia [Member] | Guidance and stabilization [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Subtotal										0	0	0
Europe and Asia [Member] | Guidance and stabilization [Member] | Other geographic areas [Member]
Segment Reporting Information [Line Items]
Subtotal										$ 0	$ 0	$ 0