Balance Sheet Components - Components of Accrued Payroll and Other Expenses (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Accrued salary and payroll related expenses	$ 6,675	$ 4,771
Accrued accounts payable	2,773	3,882
Income tax payable	434	109
Sales and use tax payable	466	365
Other	602	534
Accrued payroll and other expenses	$ 10,950	$ 9,661