Revenue Recognition - Additional Information (Detail) (USD $)	3 Months Ended				3 Months Ended	1 Months Ended		3 Months Ended		12 Months Ended	3 Months Ended		1 Months Ended	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Clinical Development	Mar. 31, 2014 Initial Commercial Sales	Mar. 31, 2014 Technology Transfer	Sep. 30, 2013 Pfizer Incorporation Nonsoftware License Arrangement	Jan. 31, 2013 Pfizer Incorporation Nonsoftware License Arrangement	Mar. 31, 2014 Pfizer Incorporation Nonsoftware License Arrangement	Mar. 31, 2013 Pfizer Incorporation Nonsoftware License Arrangement	Dec. 31, 2012 Pfizer Incorporation Nonsoftware License Arrangement	Mar. 31, 2014 Orencia Royalties from Bristol	Mar. 31, 2013 Orencia Royalties from Bristol	Jan. 30, 2014 BioMarin Pharmaceutical, Inc. Asset Purchase Agreement	Mar. 31, 2014 BioMarin Pharmaceutical, Inc. Asset Purchase Agreement	Mar. 31, 2014 BioMarin Pharmaceutical, Inc. Asset Purchase Agreement Clinical Development	Mar. 31, 2014 BioMarin Pharmaceutical, Inc. Asset Purchase Agreement Initial Commercial Sales
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Upfront Payment received under license agreement							$ 5,000,000						$ 2,000,000
Potential milestone payments to be received			60,000,000	100,000,000										160,000,000
Percentage relate to clinical development from Milestone payment															37.00%	63.00%
Provision for refund														0
License agreement, revenue recognized	2,115,000				0			0	55,000	4,876,000				2,000,000
Non-refundable up-front payment	2,000,000
Payment to be received upon signing of agreement	126,375
Revenue recognized under revenue recognition, up front payment	2,000,000
Estimated selling price					300,000
Consideration allocated to transaction					11,000
Milestone Payment			60,000,000			1,000,000
Potential milestone payments to be received								64,000,000
Royalty revenue	1,991,166	4,521,724									0	3,846,000
Percentage of royalty revenue, remittance to the University of Michigan	15.00%
Cost of royalty and other revenue		576,857									0	577,000
Revenue from sponsored research and development projects	$ 0	$ 621,000