Acquisitions - Purchase Price Allocation for Acquisition (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
SENS [Member]
Business Acquisition [Line Items]
Inventory	$ 485
Intangible assets	1,270
Total identifiable assets acquired	1,755
Accounts payable and accrued expenses	(8)
Net identifiable assets acquired	1,747
Goodwill	231
Total preliminary purchase price	1,978
GlobalTrak [Member]
Business Acquisition [Line Items]
Cash and cash equivalents	1,037
Accounts receivable	343
Inventory	1,023
Other current assets	405
Equipment	13
Intangible assets	500
Total identifiable assets acquired	3,321
Accounts payable and accrued expenses	(879)
Deferred revenues	(1,707)
Warranty	(295)
Total liabilities assumed	(2,881)
Net identifiable assets acquired	440
Goodwill	2,464
Total preliminary purchase price	2,904
MobileNet [Member]
Business Acquisition [Line Items]
Accounts receivable	363
Inventory	255
Other current assets	10
Intangible assets	3,460
Total identifiable assets acquired	4,088
Accrued expenses	(238)
Deferred revenues	(346)
Total liabilities assumed	(584)
Net identifiable assets acquired	3,504
Goodwill	2,900
Total preliminary purchase price	$ 6,404