Collaboration Revenue - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended			13 Months Ended	1 Months Ended		0 Months Ended		1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 31, 2011	Oct. 31, 2012	Nov. 30, 2011	Aug. 31, 2013	Jun. 30, 2012	Sep. 30, 2013	Dec. 18, 2013	Apr. 30, 2013	Jan. 31, 2014	Jun. 30, 2013	Mar. 31, 2013	Feb. 28, 2013	Dec. 31, 2013	Mar. 31, 2014	Dec. 31, 2014	Jan. 31, 2015	Aug. 31, 2012
Collaboration Agreements [Line Items]
Collaboration revenue	$ 45,212,000	$ 23,525,000	$ 13,706,000
Deferred revenue	113,209,000	73,571,000														73,571,000		113,209,000
Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration revenue	9,625,000	6,944,000	5,851,000
Deferred revenue	107,228,000	72,207,000														72,207,000		107,228,000
Research and Development Services
Collaboration Agreements [Line Items]
Collaboration revenue	35,587,000	16,581,000	7,855,000
ZIOPHARM Oncology, Inc.
Collaboration Agreements [Line Items]
Percent of shares outstanding at the date of achievement of future milestone				7.495%
Royalty rate as a percentage of net profit				50.00%
Required notice period for voluntary termination of collaborative agreement				90 days
ZIOPHARM Oncology, Inc. | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Deferred revenue	23,193,000	25,770,000														25,770,000		23,193,000
ZIOPHARM Oncology, Inc. | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative arrangement consideration received, shares				3,636,926
Collaborative arrangement consideration received, value				17,457,000
ZIOPHARM Oncology, Inc. | Milestone One | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative arrangement consideration received, shares					3,636,926
Collaborative arrangement consideration received, value					18,330,000
Ziopharm Oncology Ecc Separate Unit Of Accounting | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration revenue				1,115,000
Ziopharm Oncology Unit of Accounting One | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Deferred revenue				16,342,000
Synthetic Biologics Field One ECC | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative arrangement consideration received, shares						3,123,558
Collaborative arrangement consideration received, value						1,687,000
Synthetic Biologics Field Two ECC
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement							90 days
Consideration to be received upon achievement of future milestone 1																				2,000,000
Consideration to be received upon achievement of future milestone 2																				3,000,000
Synthetic Biologics Field Two ECC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Deferred revenue	6,349,000	7,000,000														7,000,000		6,349,000
Synthetic Biologics Field Two ECC | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative arrangement consideration received, shares					3,552,210
Collaborative arrangement consideration received, value					7,815,000
Synthetic Biologics, Inc.
Collaboration Agreements [Line Items]
Collaboration revenue	924,000	3,235,000	620,000
Synthetic Biologics, Inc. | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration revenue	651,000	2,187,000	293,000
Synthetic Biologics, Inc. | Research and Development Services
Collaboration Agreements [Line Items]
Collaboration revenue	273,000	1,048,000	327,000
Deferred revenue			2,500,000
Oragenics ECC
Collaboration Agreements [Line Items]
Percent of shares outstanding at the date of achievement of future milestone								1.00%
Royalty rate as a percentage of net profit								25.00%
Required notice period for voluntary termination of collaborative agreement								90 days
Percentage of shares outstanding at the date of achievement of future milestone 2								1.50%
Percentage of shares outstanding at the date of achievement of future milestone 3								2.00%
Percentage of shares outstanding at the date of achievement of future milestone 4								2.50%
Percentage of shares outstanding at the date of achievement of future milestone 5								3.00%
Oragenics ECC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Deferred revenue	5,171,000	5,720,000														5,720,000		5,171,000
Oragenics ECC | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative arrangement consideration received, shares								4,392,425
Collaborative arrangement consideration received, value								6,588,000
Oragenics Second ECC
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement									90 days
Consideration to be received upon achievement of future milestone 1									2,000,000
Consideration to be received upon achievement of future milestone 2									5,000,000
Consideration to be received upon achievement of future milestone 3									10,000,000
Royalty rate as a percentage of net sales, tier 1									10.00%
Oragenics Second ECC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Deferred revenue	4,839,000	5,335,000														5,335,000		4,839,000
Oragenics Second ECC | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative arrangement consideration received, shares									1,348,000
Collaborative arrangement consideration received, value									3,503,000
Collaborative arrangement consideration received, value of convertible promissory note									1,956,000
Maturity date of promissory note									December 31, 2013
Conversion of promissory note into Common stock										698,241
Fibrocell Science, Inc.
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement					90 days
Royalty rate as a percentage of net sales, tier 1					7.00%
Level of net sales at which royalty rate changes to tier 2					25,000,000
Royalty rate as a percentage of net sales, tier 2					14.00%
Royalty rate of savings from improvement					33.00%
Fibrocell Science, Inc. | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Deferred revenue	17,491,000	14,060,000														14,060,000		17,491,000
Fibrocell Science, Inc. | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative arrangement consideration received, shares					1,317,520
Collaborative arrangement consideration received, value					7,576,000
Number of reverse stock split											1-for-25 reverse stock split
Fibrocell Science, Inc. | Supplemental Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative arrangement consideration received, shares												1,024,590	1,243,781
Deferred revenue												5,225,000	7,612,000
Genopaver, LLC
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement														90 days
Genopaver, LLC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Deferred revenue	2,523,000	2,796,000														2,796,000		2,523,000
Genopaver, LLC | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative arrangement consideration received, value														3,000,000
AquaBounty ECC
Collaboration Agreements [Line Items]
Royalty rate as a percentage of gross profit															16.66%
S & I Ophthalmic, LLC
Collaboration Agreements [Line Items]
Collaboration revenue	2,832,000	417,000
Required notice period for voluntary termination of collaborative agreement									90 days
S & I Ophthalmic, LLC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration revenue	0	0
S & I Ophthalmic, LLC | Research and Development Services
Collaboration Agreements [Line Items]
Collaboration revenue	2,832,000	417,000
OvaXon, LLC
Collaboration Agreements [Line Items]
Collaboration revenue	2,799,000
Required notice period for voluntary termination of collaborative agreement																90 days
OvaXon, LLC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration revenue	0
OvaXon, LLC | Research and Development Services
Collaboration Agreements [Line Items]
Collaboration revenue	2,799,000
Intrexon Energy Partners, LLC
Collaboration Agreements [Line Items]
Collaboration revenue	6,102,000
Required notice period for voluntary termination of collaborative agreement																	90 days
Intrexon Energy Partners, LLC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration revenue	1,875,000
Deferred revenue	23,125,000																	23,125,000
Intrexon Energy Partners, LLC | Research and Development Services
Collaboration Agreements [Line Items]
Collaboration revenue	4,227,000
Intrexon Energy Partners, LLC | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative arrangement consideration received, value																	25,000,000
Persea Bio, LLC
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement																		90 days
Persea Bio, LLC | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative arrangement consideration received, value																		5,000,000
Persea Bio, LLC | Upfront | Upfront and Milestone Payments | Subsequent Event
Collaboration Agreements [Line Items]
Collaborative arrangement consideration received, value																			$ 5,000,000