Related Party Transactions - Additional Information (Details)				1 Months Ended								12 Months Ended
	Jan. 19, 2018	Apr. 24, 2017	Mar. 10, 2017	Dec. 31, 2017 USD ($)	Oct. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jun. 30, 2016 $ / shares shares	Nov. 30, 2015 USD ($)	Jul. 31, 2015 $ / shares shares	Mar. 31, 2015 USD ($) shares	Feb. 28, 2015 USD ($)	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 USD ($) shares	Dec. 31, 2015 USD ($) shares
Related Party Transaction [Line Items]
Sublease rental income												$ 137,000	$ 1,051,000	$ 1,486,000
Purchases of property and equipment												46,666,000	31,629,000	12,749,000
Shares issued as payment for services												11,118,000	10,777,000	2,169,000
Fair value of assets				$ 183,173,000		$ 335,307,000						183,173,000	335,307,000
Purchase of preferred stock												1,161,000	2,308,000	17,080,000
Other nonoperating income												1,013,000	1,700,000	1,314,000
ZIOPHARM Oncology, Inc.
Related Party Transaction [Line Items]
Common stock purchased from collaborative partners, value											$ 12,600,000
AmpliPhi Biosciences Corp
Related Party Transaction [Line Items]
Common stock purchased from collaborative partners, shares | shares										27,879
Warrants purchased from collaborative partners, shares | shares										6,969
Purchase of preferred stock										$ 2,300,000
Oragenics, Inc.
Related Party Transaction [Line Items]
Common stock purchased from collaborative partners, shares | shares							226,142
Price per share of common shares (in usd per share) | $ / shares							$ 5.20
Intrexon Energy Partners, LLC
Related Party Transaction [Line Items]
Purchases of property and equipment				2,812,000
Third Security
Related Party Transaction [Line Items]
Expense for services												409,000	309,000	428,000
Sublease rental income												$ 43,000	$ 43,000	$ 43,000
Services agreement, term								1 year
Shares issued as compensation for services, shares | shares												500,650	337,163	48,678
Shares issued as payment for services												$ 8,704,000	$ 8,571,000	$ 1,375,000
Harvest Intrexon Enterprise Fund I, LP
Related Party Transaction [Line Items]
Other nonoperating income												1,839,000	2,483,000	$ 1,349,000
Fibrocell Science, Inc.
Related Party Transaction [Line Items]
Common stock purchased from collaborative partners, shares | shares									125,290
Price per share of common shares (in usd per share) | $ / shares									$ 17.4
Series A Preferred Shares
Related Party Transaction [Line Items]
Convertible Preferred Shares, Conversion Price, Consecutive Trading Days					20 days
Series A Preferred Shares | Affiliates Of Third Security
Related Party Transaction [Line Items]
Convertible Preferred Stock, Amount Authorized					$ 100,000,000
Preferred stock, dividend rate, percentage					8.00%
Common Stock | Third Security
Related Party Transaction [Line Items]
Expense for services								$ 800,000
Warrants | AmpliPhi Biosciences Corp
Related Party Transaction [Line Items]
Purchase of preferred stock										321,000
Common Stock | AmpliPhi Biosciences Corp
Related Party Transaction [Line Items]
Purchase of preferred stock										$ 1,979,000
Other assets | Convertible note and warrants | Fibrocell Science, Inc.
Related Party Transaction [Line Items]
Fair value of assets				$ 575,000		1,642,000						$ 575,000	$ 1,642,000
AmpliPhi Biosciences Corp
Related Party Transaction [Line Items]
Stockholders' equity, reverse stock split		1-for-10
Stockholders' equity reverse stock split conversion ratio		0.1
Fibrocell Science, Inc.
Related Party Transaction [Line Items]
Preferred stock, dividend rate, percentage												4.00%
Stockholders' equity, reverse stock split			1-for-3
Stockholders' equity reverse stock split conversion ratio			0.3333
Third Security | Chief Executive Officer
Related Party Transaction [Line Items]
Ownership interest				100.00%								100.00%
AmpliPhi Biosciences Corp
Related Party Transaction [Line Items]
Realized investment (gain) loss						$ 4,098,000
Subsequent Event | Oragenics, Inc.
Related Party Transaction [Line Items]
Stockholders' equity, reverse stock split	1-for-10
Stockholders' equity reverse stock split conversion ratio	0.1