Components of Net Deferred Income Tax Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Net deferred income tax asset-Current
Net deferred income tax asset-Current	$ 4,601	$ 7,216
Net deferred income tax asset-Non-current
Deferred income tax asset - Non-current	15,999	14,159
Valuation Allowance	(11,576)	(11,763)
Net deferred income tax asset-Non-current	4,423	2,396
Net deferred income tax liability-Non-current
Deferred tax liability, net	1,171	1,149
Intercompany Profit In Inventory
Net deferred income tax asset-Current
Net deferred income tax asset-Current		2,252
Warranty Costs
Net deferred income tax asset-Current
Net deferred income tax asset-Current	348	290
Bad Debt Reserve
Net deferred income tax asset-Current
Net deferred income tax asset-Current	73	139
Inventory Reserve
Net deferred income tax asset-Current
Net deferred income tax asset-Current	253	1,059
Unearned Service Revenue
Net deferred income tax asset-Current
Net deferred income tax asset-Current	2,992	2,741
Net deferred income tax asset-Non-current
Deferred income tax asset - Non-current	1,654	1,522
Other
Net deferred income tax asset-Current
Net deferred income tax asset-Current	935	735
Depreciation
Net deferred income tax asset-Non-current
Deferred income tax asset - Non-current	(1,559)	(1,871)
Goodwill Amortization
Net deferred income tax asset-Non-current
Deferred income tax asset - Non-current	(1,841)	(1,675)
Product Design Costs
Net deferred income tax asset-Non-current
Deferred income tax asset - Non-current	(259)	(190)
Employee Stock Option
Net deferred income tax asset-Non-current
Deferred income tax asset - Non-current	3,021	1,548
Intangible Assets
Net deferred income tax liability-Non-current
Deferred tax liability, net	(1,171)	(1,149)
Loss Carryforwards
Net deferred income tax asset-Non-current
Deferred income tax asset - Non-current	$ 14,983	$ 14,825