Related Party Transactions - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended		1 Months Ended				6 Months Ended		1 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended			6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jan. 20, 2012 Ziopharm [Member]	Feb. 07, 2011 Ziopharm [Member]	Jan. 06, 2011 Ziopharm [Member]	Jun. 30, 2013 Ziopharm [Member]	Jun. 30, 2013 Synthetic Biologics [Member]	Jun. 30, 2013 Oragenics [Member]	Jun. 06, 2012 Affiliates Of Third Security [Member]	Jun. 06, 2011 Affiliates Of Third Security [Member]	Jun. 30, 2013 Chief Executive Officer [Member]	Jun. 30, 2012 Chief Executive Officer [Member]	Jun. 30, 2013 Chief Executive Officer [Member]	Jun. 30, 2012 Chief Executive Officer [Member]	Jun. 30, 2013 Affiliates Of Preferred Shareholders [Member] Office	Jun. 30, 2012 Affiliates Of Preferred Shareholders [Member]	Jun. 30, 2013 Affiliates Of Preferred Shareholders [Member] Office	Jun. 30, 2012 Affiliates Of Preferred Shareholders [Member]	Dec. 31, 2012 Affiliates Of Preferred Shareholders [Member] Office	Jun. 30, 2013 Soligenix Inc [Member]
Related Party Transaction [Line Items]
Payment of license fee												$ 9,000,000
Annual exclusivity fee											1,000,000
Milestone payments											54,000,000
Termination period											90 days
Compensation expense													387,000	387,000	775,000	775,000
Company leased facility																	2		2		2
Other long term assets																	66,000		66,000		66,000
Rent and other facility expenses	1,742,000	1,229,000	3,012,000	2,484,000													221,000	223,000	447,000	442,000
Shares of common stock purchased from collaborative partners					1,923,075	1,910,000	2,426,235		0	0												0
Price per share of common shares					$ 5.20	$ 5.75	$ 4.80
Purchase of additional common stock							50,000,000
Purchase commitment								$ 29,000,000
Maximum percentage of shares of future securities offerings of collaborative partners to which the entity is entitled to purchase									19.99%	30.00%
Additional shares of collaborative partner to which the entity is entitled to purchase on the open market									10.00%