Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013 M Y	Dec. 31, 2012	Dec. 31, 2011
Summary Of Significant Accounting Policies [Line Items]
Standard product warranty period	1
Deposit with financial institutions maturities period, months	3
Deposits with foreign Banks	$ 66,900,000	$ 53,200,000
Shelf life demonstration inventory, months	12
Percentage of FIFO Inventory	100.00%
Depreciation expense	5,825,000	5,769,000	5,394,000
Goodwill impairment loss	0	0	0
Valuation allowance, net deferred tax assets criterion, years	2
Income tax expense benefit	7,353,000	7,944,000	8,328,000
Uncertain Tax Position
Summary Of Significant Accounting Policies [Line Items]
Income tax expense benefit	0
Long Lived Assets
Summary Of Significant Accounting Policies [Line Items]
Assets impairment charges	$ 0	$ 0	$ 0
Minimum
Summary Of Significant Accounting Policies [Line Items]
Trade receivable time period due	30 days
Shelf life demonstration inventory, months	6
Other intangible assets, useful life	3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Trade receivable time period due	90 days
Shelf life demonstration inventory, months	12
Real property lease term, Years	7
Other intangible assets, useful life	20 years