Intangible Assets - Summary of Amortization Expenses of Purchased Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	$ 167	$ 140
Cost of net revenues
Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	0	84
General and administrative expenses
Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	167	140
Amortization expense
Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	$ 167	$ 224