Significant Customers - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Tomen Electronics Corporation
Transactions with Third Party [Line Items]
Percentage of sales revenues from distributors	14.00%	20.00%
Panasonic Communications Co., Ltd.
Transactions with Third Party [Line Items]
Percentage of sales revenues from distributors	10.00%	14.00%
VTech Holdings Ltd.
Transactions with Third Party [Line Items]
Percentage of sales revenues from distributors	34.00%	34.00%
Uniden America Corporation
Transactions with Third Party [Line Items]
Percentage of sales revenues from distributors	6.00%	16.00%
CCT Telecom Holdings Ltd
Transactions with Third Party [Line Items]
Percentage of sales revenues from distributors	10.00%	6.00%