Collaboration and License Agreements - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended			1 Months Ended		3 Months Ended		9 Months Ended		1 Months Ended	9 Months Ended			3 Months Ended	9 Months Ended		3 Months Ended	9 Months Ended	1 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		1 Months Ended					3 Months Ended	9 Months Ended			3 Months Ended		9 Months Ended		1 Months Ended	6 Months Ended	9 Months Ended			3 Months Ended		9 Months Ended			3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 PORTOLA PHARMACEUTICALS INC	Apr. 30, 2014 Biogen Idec	Nov. 30, 2012 Biogen Idec	Sep. 30, 2014 Biogen Idec	Sep. 30, 2013 Biogen Idec	Sep. 30, 2014 Biogen Idec	Sep. 30, 2013 Biogen Idec	Jan. 31, 2014 Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer")	Sep. 30, 2014 Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer")	Dec. 31, 2013 Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer")	Sep. 30, 2014 Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") October 2012 Agreement	Sep. 30, 2013 Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") October 2012 Agreement Collaborative Arrangement	Sep. 30, 2013 Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") October 2012 Agreement Collaborative Arrangement	Sep. 30, 2014 Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") January 2014 Agreement	Sep. 30, 2014 Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") January 2014 Agreement Collaborative Arrangement	Sep. 30, 2014 Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") January 2014 Agreement Collaborative Arrangement	Jan. 31, 2013 Lee's Pharmaceutical (HK) Ltd (?Lee's?)	Sep. 30, 2014 Lee's Pharmaceutical (HK) Ltd (?Lee's?)	Sep. 30, 2014 Lee's Pharmaceutical (HK) Ltd (?Lee's?) Collaborative Arrangement	Sep. 30, 2013 Lee's Pharmaceutical (HK) Ltd (?Lee's?) Collaborative Arrangement	Sep. 30, 2014 Lee's Pharmaceutical (HK) Ltd (?Lee's?) Collaborative Arrangement	Sep. 30, 2013 Lee's Pharmaceutical (HK) Ltd (?Lee's?) Collaborative Arrangement	Sep. 30, 2014 Aciex Therapeutics, Inc. ("Aciex")	Sep. 30, 2013 Aciex Therapeutics, Inc. ("Aciex")	Sep. 30, 2014 Aciex Therapeutics, Inc. ("Aciex")	Sep. 30, 2013 Aciex Therapeutics, Inc. ("Aciex")	Feb. 28, 2013 Bayer Pharma AG	Feb. 28, 2013 Janssen Pharmaceuticals, Inc.	Jan. 31, 2014 Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen")	Feb. 28, 2013 Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen")	Sep. 30, 2014 Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") January 2014 Agreement	Sep. 30, 2014 Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") January 2014 Agreement Collaborative Arrangement	Sep. 30, 2014 Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") January 2014 Agreement Collaborative Arrangement	Sep. 30, 2014 Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") January 2014 Agreement Collaborative Arrangement Future Contingent Payments	Sep. 30, 2014 Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") February 2013 Agreement	Sep. 30, 2014 Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") February 2013 Agreement Collaborative Arrangement	Sep. 30, 2013 Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") February 2013 Agreement Collaborative Arrangement	Sep. 30, 2014 Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") February 2013 Agreement Collaborative Arrangement	Sep. 30, 2013 Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") February 2013 Agreement Collaborative Arrangement	Jul. 31, 2014 Daiichi Sankyo, Inc ("Daiichi")	Jun. 30, 2013 Daiichi Sankyo, Inc ("Daiichi")	Sep. 30, 2014 Daiichi Sankyo, Inc ("Daiichi")	Mar. 31, 2014 Daiichi Sankyo, Inc ("Daiichi")	Sep. 30, 2014 Daiichi Sankyo, Inc ("Daiichi") Collaborative Arrangement	Sep. 30, 2014 Daiichi Sankyo, Inc ("Daiichi") June Two Thousand Thirteen Agreement Collaborative Arrangement	Sep. 30, 2013 Daiichi Sankyo, Inc ("Daiichi") June Two Thousand Thirteen Agreement Collaborative Arrangement	Sep. 30, 2014 Daiichi Sankyo, Inc ("Daiichi") June Two Thousand Thirteen Agreement Collaborative Arrangement	Sep. 30, 2013 Daiichi Sankyo, Inc ("Daiichi") June Two Thousand Thirteen Agreement Collaborative Arrangement	Sep. 30, 2014 Daiichi Sankyo, Inc ("Daiichi") July 2014 Agreement	Sep. 30, 2014 Daiichi Sankyo, Inc ("Daiichi") July 2014 Agreement Collaborative Arrangement	Sep. 30, 2014 Daiichi Sankyo, Inc ("Daiichi") July 2014 Agreement Collaborative Arrangement	Sep. 30, 2014 Daiichi Sankyo, Inc ("Daiichi") July 2014 Agreement Collaborative Arrangement Future Contingent Payments
Research And Development Arrangement Contract To Perform For Others [Line Items]
License fee receivable upon occurrence of certain development and regulatory events							$ 370,000,000
Notice period for agreement termination							120 days														60 days
Payments Upon the Completion of Certain Commercial Milestones						15,000,000
Reduction in research and development expense								23,080	227,000	179,000	721,000
Deferred revenue														6,000,000	0			11,900,000				300,000													11,300,000				0									1,300,000					14,100,000
Collaboration revenue recognized																772,000	3,900,000		164,000	1,100,000			64,000	78,000	189,000	130,000										361,000	1,700,000	0		316,000	1,000,000	1,100,000	3,500,000						662,000	888,000	2,300,000	1,000,000		861,000	861,000	0
Upfront fee												13,000,000									700,000										2,500,000	2,500,000	10,000,000	5,000,000										15,000,000
Milestone Payments of Development and Regulatory Event												12,000,000																					8,000,000											20,000,000
Percentage of consideration received under agreement												50.00%
Non-contingent consideration being recognized as revenue over estimated period of performance													6,500,000																																		3,000,000
Contingent consideration to be recognized after resolution of contingency													6,500,000																																	3,000,000
Development costs, percent					40.00%																								60.00%
Research and development	31,780,000	18,088,000	88,918,000	56,642,000																							0	0	0	0
Percentage of profits entitle to receive under agreement																													50.00%
Additional non-refundable fee																															250,000	250,000		500,000
Contingent payment payable upon achievement																																	7,000,000											5,000,000
Contingent Payments Received																																					3,000,000
Collaborative arrangement upfront payment to be received																																													6,000,000
Upfront fee subject to refund																																													$ 3,000,000