Common Stock, Additional Capital Shares Reserved for Future Issuance

No definition available.

Name:	sgmo_CommonStockAdditionalCapitalSharesReservedForFutureIssuance
Namespace Prefix:	sgmo_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Common stock exchange ratio.

+ References

No definition available.

+ Details

Name:	sgmo_CommonStockExchangeRatio
Namespace Prefix:	sgmo_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Purchase plan offering period.

+ References

No definition available.

+ Details

Name:	sgmo_PurchasePlanOfferingPeriod
Namespace Prefix:	sgmo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Purchase plan purchase period.

+ References

No definition available.

+ Details

Name:	sgmo_PurchasePlanPurchasePeriod
Namespace Prefix:	sgmo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Sale Of Stock, Increase To Aggregate Offering Price

+ References

No definition available.

+ Details

Name:	sgmo_SaleOfStockIncreaseToAggregateOfferingPrice
Namespace Prefix:	sgmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award options expiration term.

+ References

No definition available.

+ Details

Name:	sgmo_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationTerm
Namespace Prefix:	sgmo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award options maximum term for specified stock holder.

+ References

No definition available.

+ Details

Name:	sgmo_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsMaximumTermForSpecifiedStockHolder
Namespace Prefix:	sgmo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award purchase price of common stock percent for specified stockholder.

+ References

No definition available.

+ Details

Name:	sgmo_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePriceOfCommonStockPercentForSpecifiedStockholder
Namespace Prefix:	sgmo_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Specified stockholder ownership percentage.

+ References

No definition available.

+ Details

Name:	sgmo_SpecifiedStockholderOwnershipPercentage
Namespace Prefix:	sgmo_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Stock Offering Program, Maximum Value

+ References

No definition available.

+ Details

Name:	sgmo_StockOfferingProgramMaximumValue
Namespace Prefix:	sgmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Aggregate number of common shares reserved for future issuance.

+ References

+ Details

Name:	us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

+ References

+ Details

Name:	us-gaap_CommonStockSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockSharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of cash outflow to satisfy grantee's tax withholding obligation for award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3291-108585

+ Details

Name:	us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

+ References

+ Details

Name:	us-gaap_PreferredStockSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.

+ References

+ Details

Name:	us-gaap_PreferredStockSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

+ References

+ Details

Name:	us-gaap_PreferredStockSharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Cash received on stock transaction after deduction of issuance costs.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockConsiderationReceivedOnTransaction
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares authorized for issuance under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Intrinsic value of vested award under share-based payment arrangement. Excludes share and unit options.

+ References

No definition available.

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVested
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Purchase price of common stock expressed as a percentage of its fair value.

+ References

No definition available.

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares used to settle grantee's tax withholding obligation for award under share-based payment arrangement.

+ References

No definition available.

+ Details

Name:	us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of new stock issued during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21463-112644

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB TOPIC 4.C)
-URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187143-122770

+ Details

Name:	us-gaap_StockholdersEquityNoteStockSplitConversionRatio1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=sgmo_Restated2018StockIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=sgmo_TwoThousandEighteenStockIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=sgmo_EmployeeStockPurchasePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=sgmo_JefferiesLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=sgmo_AtTheMarketOfferingAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=sgmo_StockPurchaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=sgmo_BiogenMAIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

STOCKHOLDERS' EQUITY - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended				12 Months Ended
	Dec. 31, 2022	May 31, 2021	Aug. 31, 2020	Apr. 30, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	May 31, 2022	Jun. 30, 2020	Jun. 29, 2020	May 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred shares authorized (in shares)	5,000,000				5,000,000	5,000,000
Preferred stock issued (in shares)	0				0	0
Preferred stock outstanding (in shares)	0				0	0
Common stock, shares authorized (in shares)	320,000,000				320,000,000	320,000,000			320,000,000	160,000,000
Common stock, shares outstanding (in shares)	166,793,320				166,793,320	145,921,530
Stock option maximum term					5 years 9 months 29 days
Specified stockholder ownership percentage					10.00%
Purchase price of common stock percent under stock incentive plans for specified stockholder					110.00%
Stock option maximum term for specified stockholder					5 years
Share of common stock subject to a stock option or stock appreciation right (in shares)	100.00%				100.00%
Shares reserved for issuance of future awards (in shares)	4,205,502				4,205,502
Intrinsic value of options exercised					$ 0	$ 2,800	$ 5,400
Options exercisable, aggregate intrinsic value	$ 0				$ 0
Restricted stock units awarded (in shares)					4,349,795
Total payments for the employees' tax obligations to taxing authorities					$ 2,104	$ 3,258	$ 765
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period					3 years
Restricted stock units awarded (in shares)					4,349,795	2,140,785	2,517,101
Grant date fair value per award of restricted stock units (in dollars per share)					$ 5.52	$ 11.16	$ 8.06
Aggregate fair value of RSUs vested in period					$ 13,100	$ 9,000	$ 3,700
Shares withheld from issuance in order to pay employee taxes (in shares)					380,917	293,120	90,617
Restated 2018 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in capital shares reserved for future issuance (in shares)								7,900,000			9,900,000
2018 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of fair value per share of common stock on option grant date					100.00%
Stock options expiration term					10 years
Fixed ratio shares of common stock					1.33
Shares reserved for issuance of future awards (in shares)	9,869,961				9,869,961
2010 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of fair value per share of common stock on option grant date		85.00%
Stock reserved for issuance under plan (in shares)		5,000,000
Purchase plan offering period		2 years
Purchase plan purchase period		6 months
Maximum \| 2018 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option maximum term					10 years
Stock options vesting period					4 years
Minimum \| 2018 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period					3 years
Jefferies LLC \| ATM Agreement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Consideration received from sale of stock					$ 84,900	$ 27,100
Issuance of common stock, net (in shares)					19,300,743	2,007,932
Stock offering program, maximum value			$ 150,000
Stock offering program, increase to aggregate offering price	$ 175,000
Stock Purchase Agreement \| Biogen MA, Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sale of stock, price per share (in dollars per share)				$ 9.2137
Consideration received from sale of stock				$ 225,000