Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Collaboration and license revenue	$ 4,231	$ 2,385	$ 12,489	$ 4,744
Operating expenses:
Research and development	44,823	52,300	103,636	92,158
Selling, general and administrative	17,044	8,912	31,795	17,917
Total operating expenses	61,867	61,212	135,431	110,075
Loss from operations	(57,636)	(58,827)	(122,942)	(105,331)
Interest and other income (expense), net	297	498	629	89
Net loss	(57,339)	(58,329)	(122,313)	(105,242)
Net loss attributable to Portola	$ (57,339)	$ (58,329)	$ (122,313)	$ (105,242)
Net loss per share attributable to Portola common stockholders:
Basic and diluted	$ (1.02)	$ (1.12)	$ (2.17)	$ (2.07)
Shares used to compute net loss per share attributable to Portola common stockholders:
Basic and diluted	56,399,535	52,147,146	56,434,644	50,844,697