Collaboration and Licensing Revenue - Additional Information (Details)			1 Months Ended																				5 Months Ended	12 Months Ended
	Jan. 19, 2018	Mar. 10, 2017	Dec. 31, 2017 USD ($)	Nov. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($) shares	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) shares	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	May 31, 2015 USD ($) target	Dec. 31, 2014 USD ($)	Mar. 31, 2014 USD ($)	Jan. 31, 2014 USD ($) shares	Dec. 31, 2013 shares	Sep. 30, 2013 USD ($) shares	Jun. 30, 2013 USD ($) shares	Mar. 31, 2013 USD ($)	Feb. 28, 2013	Oct. 31, 2012 USD ($) shares	Jun. 30, 2012 USD ($) shares	Jan. 31, 2011 USD ($) shares	May 31, 2016	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								$ 145,579,000	$ 109,871,000	$ 87,821,000
Deferred revenue			$ 236,397,000																					236,397,000	310,142,000
Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								71,637,000	34,433,000	32,513,000
Deferred revenue			230,531,000																					230,531,000	297,867,000
Prepaid research and development services
Collaboration Agreements [Line Items]
Deferred revenue			1,052,000																					1,052,000	6,015,000
ZIOPHARM ECC 1
Collaboration Agreements [Line Items]
Percentage of shares outstanding at the date of achievement of future milestone																						7.495%
Required notice period for voluntary termination of collaborative agreement																						90 days
ZIOPHARM ECC 1 | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received (in shares) | shares																						3,636,926
Collaborative agreement, consideration received, value																						$ 17,457,000
ZIOPHARM ECC 1 | Milestone One | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received (in shares) | shares																				3,636,926
Collaborative agreement, consideration received, value																				$ 18,330,000
ZIOPHARM ECC 1 Separate Unit Of Accounting | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																						1,115,000
ZIOPHARM ECC 1 Unit of Accounting 1 | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Deferred revenue																						$ 16,342,000
ZIOPHARM Oncology, Inc.
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								69,812,000	33,836,000	19,306,000
Royalty rate as a percentage of net profit						20.00%																	50.00%
ZIOPHARM Oncology, Inc. | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								48,313,000	11,529,000	2,855,000
Deferred revenue			90,496,000																					90,496,000	138,809,000
ZIOPHARM Oncology, Inc. | Other Contractual Payments | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value						$ 120,000,000
Collaborative arrangement consideration received, number of preferred shares (in shares) | shares						100,000
Ares Trading S.A.
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								10,738,000	10,192,000	4,728,000
Required notice period for voluntary termination of collaborative agreement											90 days
Collaborative agreement, additional target fee											$ 5,000,000
Ares Trading S.A. | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								6,389,000	6,389,000	3,933,000
Deferred revenue			40,789,000																					40,789,000	47,178,000
Ares Trading S.A. | Prepaid research and development services
Collaboration Agreements [Line Items]
Deferred revenue											$ 10,000,000
Collaborative agreement, consideration receivable, minimum targets required | target											2
Collaborative agreement, consideration receivable, collection period											2 years
Ares Trading S.A. | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value											$ 115,000,000
ZIOPHARM ECC 2 | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value									$ 10,000,000
Collaboration and licensing revenues			28,943,000
Oragenics ECC 1
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement																					90 days
Royalty rate as a percentage of net profit																					25.00%
Oragenics ECC 1 | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received (in shares) | shares																					439,243
Collaborative agreement, consideration received, value																					$ 6,588,000
Oragenics ECC 2 | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received (in shares) | shares																134,800
Collaborative agreement, consideration received, value																$ 3,503,000
Collaborative agreement, consideration received, value of convertible promissory note																$ 1,956,000
Conversion of promissory note into common stock (in shares) | shares															69,824
Oragenics ECC 3
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement										90 days
Oragenics ECC 3 | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value of convertible promissory note										$ 5,000,000
Conversion of promissory note into common stock (in shares) | shares								338,100
Fibrocell ECC 1
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 ECC 1 | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received (in shares) | shares																				439,173
Collaborative agreement, consideration received, value																				$ 7,576,000
Fibrocell ECC 1 | Supplemental Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received (in shares) | shares														341,530			414,594
Collaborative agreement, consideration received, value														$ 5,225,000			$ 7,612,000
Fibrocell ECC 2
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement								90 days
Maximum milestone payments required upon successful achievement, first product								$ 30,000,000
Maximum milestone payments required upon successful achievement, per each additional product								30,000,000
Maximum milestone payments required for certain sales milestones, per product								22,500,000
Fibrocell ECC 2 | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value								$ 10,000,000
Genopaver, LLC
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								6,690,000	6,117,000	3,829,000
Required notice period for voluntary termination of collaborative agreement																		90 days
Genopaver, LLC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								273,000	273,000	273,000
Deferred revenue			1,704,000																					1,704,000	1,977,000
Genopaver, LLC | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value																		$ 3,000,000
AquaBounty Technologies, Inc.
Collaboration Agreements [Line Items]
Royalty rate as a percentage of gross profit																			16.66%
S & I Ophthalmic, LLC
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								755,000	6,141,000	4,115,000
S & I Ophthalmic, LLC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								0	0	0
OvaXon, LLC
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								1,966,000	2,934,000	2,540,000
Required notice period for voluntary termination of collaborative agreement															90 days
OvaXon, LLC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								0	0	0
Intrexon Energy Partners, LLC
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								10,665,000	17,552,000	13,447,000
Required notice period for voluntary termination of collaborative agreement													90 days
Intrexon Energy Partners, LLC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								2,500,000	2,500,000	2,500,000
Deferred revenue			15,625,000																					15,625,000	18,125,000
Intrexon Energy Partners, LLC | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value													$ 25,000,000
Persea Bio, LLC
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								946,000	1,278,000	1,241,000
Required notice period for voluntary termination of collaborative agreement												90 days
Persea Bio, LLC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								500,000	500,000	500,000
Deferred revenue			3,500,000																					3,500,000	4,000,000
Persea Bio, LLC | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value												$ 5,000,000
Thrive Agrobiotics, Inc.
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement									90 days
Thrive Agrobiotics, Inc. | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value									$ 1,667,000
Intrexon Energy Partners II, LLC
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								3,672,000	3,169,000	167,000
Required notice period for voluntary termination of collaborative agreement								90 days
Intrexon Energy Partners II, LLC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								2,000,000	2,000,000	$ 167,000
Deferred revenue			13,833,000																					13,833,000	15,833,000
Intrexon Energy Partners II, LLC | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value								$ 18,000,000
Exotech Bio, Inc.
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement							90 days
Exotech Bio, Inc. | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value							$ 5,000,000
Relieve Genetics, Inc.
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement							90 days
Relieve Genetics, Inc. | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value							$ 4,333,000
Intrexon T1D Partners, LLC
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								5,968,000	1,908,000
Required notice period for voluntary termination of collaborative agreement							90 days
Intrexon T1D Partners, LLC | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaboration and licensing revenues																								1,109,000	821,000
Deferred revenue			$ 8,435,000																					$ 8,435,000	$ 8,653,000
Intrexon T1D Partners, LLC | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value							$ 10,000,000
AD Skincare, Inc.
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement						90 days
AD Skincare, Inc. | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value						$ 4,333,000
Genten Therapeutics, Inc.
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement					90 days
Genten Therapeutics, Inc. | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value					$ 3,000,000
Collaborative agreement, consideration received, cash					$ 1,500,000
CRS Bio, Inc.
Collaboration Agreements [Line Items]
Required notice period for voluntary termination of collaborative agreement					90 days
CRS Bio, Inc. | Upfront | Upfront and Milestone Payments
Collaboration Agreements [Line Items]
Collaborative agreement, consideration received, value					$ 2,100,000
ZIOPHARM Oncology, Inc. | Ares Trading S.A.
Collaboration Agreements [Line Items]
Collaboration agreement, percent of collaboration payments																								50.00%
Payments to related parties											57,500,000
Maximum | Ares Trading S.A.
Collaboration Agreements [Line Items]
Milestone payments required upon successful achievement, per product											413,000,000
Milestone payments required upon successful achievement, one-time											$ 50,000,000
Maximum | Oragenics ECC 1
Collaboration Agreements [Line Items]
Milestone payments required upon successful achievement, one-time				$ 35,000,000
Maximum | Oragenics ECC 3
Collaboration Agreements [Line Items]
Milestone payments required upon successful achievement, per product				$ 5,500,000						22,000,000
Milestone payments required upon successful achievement, one-time										$ 10,000,000
Maximum | Thrive Agrobiotics, Inc.
Collaboration Agreements [Line Items]
Milestone payments required upon successful achievement, per product									$ 5,500,000
Maximum | Exotech Bio, Inc.
Collaboration Agreements [Line Items]
Milestone payments required upon successful achievement, per product							52,500,000
Maximum | Relieve Genetics, Inc.
Collaboration Agreements [Line Items]
Milestone payments required upon successful achievement, per product							$ 52,500,000
Maximum | AD Skincare, Inc.
Collaboration Agreements [Line Items]
Milestone payments required upon successful achievement, per product						2,000,000
Milestone payments required upon successful achievement, one-time						$ 17,000,000
Maximum | Genten Therapeutics, Inc.
Collaboration Agreements [Line Items]
Milestone payments required upon successful achievement, per product					82,000,000
Maximum | CRS Bio, Inc.
Collaboration Agreements [Line Items]
Milestone payments required upon successful achievement, per product					$ 75,000,000
Fibrocell Science, Inc.
Collaboration Agreements [Line Items]
Stockholders' equity, reverse stock split		1-for-3
Stockholders' equity reverse stock split conversion ratio		0.3333
Subsequent Event | Oragenics, Inc.
Collaboration Agreements [Line Items]
Stockholders' equity, reverse stock split	1-for-10
Stockholders' equity reverse stock split conversion ratio	0.1