Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Collaboration and license revenue	$ 3,787	$ 4,231	$ 8,915	$ 12,489
Operating expenses:
Research and development	49,292	44,823	79,937	103,636
Selling, general and administrative	20,329	17,044	35,350	31,795
Total operating expenses	69,621	61,867	115,287	135,431
Loss from operations	(65,834)	(57,636)	(106,372)	(122,942)
Interest and other income (expense), net	(124)	297	289	629
Interest expense	(3,456)		(5,095)
Net loss	(69,414)	(57,339)	(111,178)	(122,313)
Net income attributable to noncontrolling interest (SRX Cardio)	(240)		(195)
Net loss attributable to Portola	$ (69,654)	$ (57,339)	$ (111,373)	$ (122,313)
Net loss per share attributable to Portola common stockholders:
Basic and diluted	$ (1.22)	$ (1.02)	$ (1.96)	$ (2.17)
Shares used to compute net loss per share attributable to Portola common stockholders:
Basic and diluted	57,050,523	56,399,535	56,872,644	56,434,644