Goodwill and Intangible Assets - Components of Goodwill (Detail) (USD $) In Thousands, unless otherwise specified			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 MobileNet [Member]	Dec. 31, 2013 GlobalTrak [Member]	Dec. 31, 2013 SENS [Member]
Goodwill [Line Items]
Beginning balance	$ 20,335	$ 14,740
Addition resulting from the acquisition			2,900	2,464	231
Ending balance	$ 20,335	$ 14,740