Stock-Based Compensation Expense (Detail) (Stock Based Compensation Expense, USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated share based compensation expense	$ 1,590,000	$ 1,282,000	$ 4,265,000	$ 3,435,000
Cost of Goods Sold
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated share based compensation expense	471,000	228,000	845,000	553,000
Research and Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated share based compensation expense	417,000	404,000	1,435,000	1,268,000
Selling and Marketing Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated share based compensation expense	253,000	242,000	835,000	656,000
General and Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated share based compensation expense	$ 449,000	$ 408,000	$ 1,150,000	$ 958,000