Summarized Amount of Collaboration Recorded in Consolidated Statement of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	$ 7,837	$ 3,864
ZIOPHARM Oncology, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	2,680	2,074
Synthetic Biologics, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	359	570
Oragenics, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	795	516
Fibrocell Science, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	1,310	588
Genopaver, LLC
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	490
S & I Ophthalmic, LLC
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	879
OvaXon, LLC
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	169
Other Collaborations
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	1,155	116
Upfront and Milestone Payments
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	1,882	1,137
Upfront and Milestone Payments | ZIOPHARM Oncology, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	644	644
Upfront and Milestone Payments | Synthetic Biologics, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	162	195
Upfront and Milestone Payments | Oragenics, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	262	137
Upfront and Milestone Payments | Fibrocell Science, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	448	158
Upfront and Milestone Payments | Genopaver, LLC
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	69
Upfront and Milestone Payments | Other Collaborations
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	297	3
Research And Development Services
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	5,955	2,727
Research And Development Services | ZIOPHARM Oncology, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	2,036	1,430
Research And Development Services | Synthetic Biologics, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	197	375
Research And Development Services | Oragenics, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	533	379
Research And Development Services | Fibrocell Science, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	862	430
Research And Development Services | Genopaver, LLC
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	421
Research And Development Services | S & I Ophthalmic, LLC
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	879
Research And Development Services | OvaXon, LLC
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	169
Research And Development Services | Other Collaborations
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenues	$ 858	$ 113