Revenue Recognition - Additional Information (Detail) (USD $)	3 Months Ended			6 Months Ended		3 Months Ended		6 Months Ended		0 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended	3 Months Ended		6 Months Ended		0 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Mar. 31, 2014 Technology Transfer	Jun. 30, 2014 Technology Transfer	Jun. 30, 2014 Clinical Development	Jun. 30, 2014 Initial Commercial Sales	Sep. 04, 2013 Pfizer Incorporation Nonsoftware License Arrangement	Jan. 22, 2013 Pfizer Incorporation Nonsoftware License Arrangement	Jun. 30, 2014 Pfizer Incorporation Nonsoftware License Arrangement	Jun. 30, 2013 Pfizer Incorporation Nonsoftware License Arrangement	Jun. 30, 2014 Pfizer Incorporation Nonsoftware License Arrangement	Jun. 30, 2013 Pfizer Incorporation Nonsoftware License Arrangement	Dec. 31, 2012 Pfizer Incorporation Nonsoftware License Arrangement	Jun. 30, 2014 Orencia Royalties from Bristol	Jun. 30, 2013 Orencia Royalties from Bristol	Jun. 30, 2014 Orencia Royalties from Bristol	Jun. 30, 2013 Orencia Royalties from Bristol	Jan. 30, 2014 BioMarin Pharmaceutical, Inc. Asset Purchase Agreement	Mar. 31, 2014 BioMarin Pharmaceutical, Inc. Asset Purchase Agreement	Jun. 30, 2014 BioMarin Pharmaceutical, Inc. Asset Purchase Agreement	Jun. 30, 2014 BioMarin Pharmaceutical, Inc. Asset Purchase Agreement Clinical Development	Jun. 30, 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	69,000	0	124,000	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		64,000,000
Royalty revenue			4,495,357	1,991,166	9,017,081												0	4,285,000	0	8,131,000
Percentage of royalty revenue, remittance to the University of Michigan				15.00%
Cost of royalty revenue			642,736		1,219,593												0	643,000	0	1,220,000
Revenue from sponsored research and development projects	$ 0		$ 142,000	$ 0	$ 762,000