Document and Entity Information	6 Months Ended
	Jun. 30, 2013
Document Information [Line Items]
Document Type	S-1
Amendment Flag	false
Document Period End Date	Jun. 30, 2013
Trading Symbol	PTLA
Entity Registrant Name	PORTOLA PHARMACEUTICALS INC.
Entity Central Index Key	0001269021
Entity Filer Category	Non-accelerated Filer