CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income	Non- Controlling Interest
Beginning Balances (in shares) at Dec. 31, 2019		115,972,708
Beginning Balances at Dec. 31, 2019	$ 432,739	$ 1,160	$ 1,090,828	$ (656,985)	$ (2,449)	$ 185
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and in connection with restricted stock units, net of tax (in shares)		305,845
Issuance of common stock upon exercise of stock options and in connection with restricted stock units, net of tax	409	$ 3	406
Stock-based compensation	5,620		5,620
Foreign currency translation adjustment	(1,633)				(1,633)
Net unrealized loss on marketable securities, net of tax	254				254
Net loss	(42,974)			(42,913)		(61)
Ending Balances (in shares) at Mar. 31, 2020		116,278,553
Ending Balances at Mar. 31, 2020	394,415	$ 1,163	1,096,854	(699,898)	(3,828)	124
Beginning Balances (in shares) at Dec. 31, 2020		142,063,203
Beginning Balances at Dec. 31, 2020	497,366	$ 1,421	1,269,375	(777,981)	5,419	(868)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock in connection with at-the-market offering, net of offering expenses (in shares)		1,034,762
Issuance of common stock in connection with at-the-market offering, net of offering expenses	15,651	$ 10	15,641
Issuance of common stock upon exercise of stock options and in connection with restricted stock units, net of tax (in shares)		615,800
Issuance of common stock upon exercise of stock options and in connection with restricted stock units, net of tax	(416)	$ 6	(422)
Stock-based compensation	7,524		7,524
Acquisition of additional shares of Sangamo France	(64)					(64)
Foreign currency translation adjustment	(4,749)				(4,749)
Net unrealized loss on marketable securities, net of tax	44				44
Net loss	(45,939)			(45,933)		(6)
Ending Balances (in shares) at Mar. 31, 2021		143,713,765
Ending Balances at Mar. 31, 2021	$ 469,417	$ 1,437	$ 1,292,118	$ (823,914)	$ 714	$ (938)