Stock-Based Compensation Expense Resulting from ESPP (Detail) (2011 Employee Stock Purchase Plan, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Equity Based Compensation Related To Employee Stock Purchase Programs [Line Items]
Stock-Based Compensation Expense	$ 64
Cost of revenue
Equity Based Compensation Related To Employee Stock Purchase Programs [Line Items]
Stock-Based Compensation Expense	16
Research and development
Equity Based Compensation Related To Employee Stock Purchase Programs [Line Items]
Stock-Based Compensation Expense	12
Selling and marketing
Equity Based Compensation Related To Employee Stock Purchase Programs [Line Items]
Stock-Based Compensation Expense	19
General and administrative
Equity Based Compensation Related To Employee Stock Purchase Programs [Line Items]
Stock-Based Compensation Expense	$ 17