CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
Net loss	$ (43,173)	$ (47,174)	$ (87,150)	$ (93,113)
Foreign currency translation adjustment	(6,108)	1,308	(8,012)	(3,441)
Net pension gains	56	0	75	0
Unrealized (loss) gain on marketable securities, net of tax	(153)	(35)	(1,236)	9
Comprehensive loss	(49,378)	(45,901)	(96,323)	(96,545)
Comprehensive loss attributable to non-controlling interest	0	(5)	0	(11)
Comprehensive loss attributable to Sangamo Therapeutics, Inc.	$ (49,378)	$ (45,896)	$ (96,323)	$ (96,534)