Settlement of a Related Party Relationship - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended				12 Months Ended
	Oct. 05, 2018	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Transaction advisory costs recognized as expense						$ 2,000
Related Party Transaction, Amounts of Transaction		$ 207,361	$ 0	$ 0	$ 0
Research and development expense						34,134	$ 45,084	$ 157,791
Preferred Stock Redemption Discount						207,361
Gorilla IL-12 Products
Percentage of development cost shared by other party	80.00%
Percentage of operating profit shared by other party	80.00%
Intrexon Corporation/Precigen
Annual Licensing fee	$ 100
Reimbursement of historical costs	1,000
Preferred Stock, Contract Liability, Derivative Liability	163,300
Increase in accumulated deficit	49,500
Related Party Transaction, Amounts of Transaction	212,800
Research and development expense						$ 1,000
Additional milestone payment for exclusively licensed program to be paid	52,500
Maximum Royalty payable	$ 100,000
Percentage of sublicensing income	20.00%
Royalty payment to be received	$ 50,000
Intrexon Corporation/Precigen | Gorilla IL-12 Products
Percentage of development cost shared by other party	20.00%
Percentage of operating profit shared by other party	20.00%
Third Party Vendor
Transaction advisory costs recognized as expense	$ 7,400
Series 1 Preferred Stock [Member]
Transaction advisory costs recognized as expense	5,400
Series 1 Preferred Stock [Member] | Intrexon Corporation/Precigen
Consideration transferred	5,400
Preferred Stock Redemption Discount	$ 207,300