Related Party Transactions - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands								1 Months Ended	3 Months Ended				9 Months Ended		12 Months Ended
	Jun. 29, 2016	Jan. 08, 2016	Sep. 28, 2015	Jun. 29, 2015	Mar. 27, 2015	Feb. 03, 2015	Jan. 06, 2011	Sep. 30, 2015	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2015	Dec. 31, 2017
Related Party Transaction [Line Items]
Company re-purchased additional shares Value													$ 1,275
Change in fair value of derivative liability									$ (165)	$ 183	$ 28	$ 202	46	$ (1,292)
Research and Development Expense									$ 8,263			11,105	$ 25,935	33,903
Series 1 Preferred Stock
Related Party Transaction [Line Items]
Preferred stock, stated value									$ 1,200				$ 1,200			$ 1,200
Temporary equity, fair value									$ 6,100				$ 16,700
License Agreement | M.D. Anderson Cancer Center
Related Party Transaction [Line Items]
Issuance of common stock in licensing agreement (in shares)													11,722,163		11,722,163
Research and Development Expense													$ 67,300		$ 67,300
Cooperative Research and Development Agreement | M.D. Anderson Cancer Center
Related Party Transaction [Line Items]
Research and Development Service Agreement Quarterly Payment											2,700		2,700	9,300
Research and Development Service Agreement Aggregate Payments											$ 41,900
Intrexon Corporation/Precigen
Related Party Transaction [Line Items]
Stock issued during period						1,440,000
Percentage of commitment for payments from receipts of upfronts, milestones and royalties					50.00%
Commitment to purchase common stock					$ 43,500		$ 50,000
Stock buy back (Shares)				3,711
Stock buy back				$ 34
Share buy back discount on closing price				5.00%
Company re-purchased additional shares		168
Company re-purchased additional shares Value		$ 2
Amounts expensed for services incurred									2,000			5,600	6,700	16,800
Amount due to related party, current									$ 2,900			$ 5,500	$ 2,900	$ 5,500
Intrexon Corporation/Precigen | Series 1 Preferred Stock
Related Party Transaction [Line Items]
Issuance of common stock in licensing agreement (in shares)	100,000								3,847				11,205
Preferred stock, stated value	$ 1,200
Dividends, preferred stock	$ 12.00
Intrexon Corporation/Precigen | 2016 GvHD Amendment
Related Party Transaction [Line Items]
Research and Development Expense								$ 10,000
Intrexon Corporation/Precigen | 2016 GvHD Amendment | License
Related Party Transaction [Line Items]
Licensing fee			$ 10,000
Intrexon Corporation/Precigen | 2016 GvHD Amendment | Quarterly Payment | After Amendment
Related Party Transaction [Line Items]
Royalty percentage of net profit	20.00%
Intrexon Corporation/Precigen | 2016 GvHD Amendment | Quarterly Payment | Before Amendment
Related Party Transaction [Line Items]
Royalty percentage of net profit	50.00%
Intrexon Corporation/Precigen | ECP Channel Agreement | Quarterly Payment
Related Party Transaction [Line Items]
Royalty percentage of net profit							20.00%
Intrexon Corporation/Precigen | ECP Channel Agreement | Quarterly Payment | After Amendment
Related Party Transaction [Line Items]
Royalty percentage of net profit	20.00%
Intrexon Corporation/Precigen | ECP Channel Agreement | Quarterly Payment | Before Amendment
Related Party Transaction [Line Items]
Royalty percentage of net profit	50.00%