Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2015		Dec. 31, 2014
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 15,228		$ 10,477
Less accumulated depreciation and amortization	(8,985)		(7,701)
Property and equipment, net	6,243	[1]	2,776
Computer equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	960		734
Capitalized software
Property Plant And Equipment [Line Items]
Property and equipment, gross	865		674
Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	5,874		4,852
Leasehold improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 7,529		$ 4,217

[1] Amounts include the assets and liabilities of a consolidated variable interest entity (“VIE”). Portola's interests and obligations with respect to the VIE's assets and liabilities are limited to those accorded to Portola in its agreement with the VIE. See Note 8, “Asset Acquisition and License Agreements,” to these consolidated financial statements.