Other Balance Sheet Accounts - Summary of Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Total of summary of intangible assets	$ 3,968	$ 10,435
Net total of intangible assets	1,972	2,813
Licensed technology rights [Member]
Finite-Lived Intangible Assets [Line Items]
Total of summary of intangible assets		4,015
Accumulated amortization		(3,931)
Patent application costs [Member]
Finite-Lived Intangible Assets [Line Items]
Total of summary of intangible assets	3,968	6,420
Accumulated amortization	$ (1,996)	$ (3,691)