Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
	Jan. 02, 2018	Jun. 29, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Feb. 28, 2019	Sep. 30, 2018	Jan. 01, 2018
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses			$ 7,534	$ 8,454	$ 8,452
Weighted average fair value of stock option granted			$ 1.64	$ 3.94	$ 4.43
Accumulated deficit			$ (566,329)	$ (712,442)
Transaction Price			57,500
Deferred revenue - current portion				6,389			$ 49,500
Impact On Assets and Liabilities			1,700
Payments to Acquire Joint Venture			35,000
Contract liability			$ (146)	(6,389)	$ (6,861)
Difference between revenue guidance in effect before and after topic 606
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit								$ 8,100
Research and Development Services Contract Term			9 years
Contract liability	$ 8,100
Stock Options
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses			$ 3,000	2,500	3,000
Restricted Stock
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses			4,500	$ 6,000	$ 5,500
Current Assets | Lease Obligations
Summary Of Significant Accounting Policies [Line Items]
Restricted cash			$ 105
Minimum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment useful life			3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment useful life			5 years
Subsequent Event | CRADA agreement
Summary Of Significant Accounting Policies [Line Items]
Committed Amount						$ 5,000
ASU 2014-09
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit								(720,573)
Deferred revenue - current portion								622
Contract liability			$ 0
ASU 2014-09 | Difference between revenue guidance in effect before and after topic 606
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit								(8,131)
Deferred revenue - current portion								$ (5,767)
Contract liability			$ 0
Intrexon Corporation/Precigen | Series 1 Preferred Stock
Summary Of Significant Accounting Policies [Line Items]
Issuance of stock in a license agreement (in shares)		100,000	11,415