Other Balance Sheet Accounts - Summary of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Total of property and equipment	$ 26,075	$ 27,652
Less accumulated depreciation and amortization	(22,140)	(22,368)
Property and equipment, net	3,935	5,284
Equipment [Member]
Property, Plant and Equipment [Line Items]
Total of property and equipment	18,027	19,660
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total of property and equipment	$ 8,048	$ 7,992