XML 47 R37.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions | 1 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Apr. 30, 2018 | Sep. 30, 2018 | Sep. 30, 2017 | May 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Net proceeds from sale of shares, after deducting underwriting discounts and commissions and other estimated offering expenses |  | $ 215,757,000 | $ 81,573,000 |
ATM Agreement [Member] |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Common stock issuable and sellable under offering agreement |  | $ 75,000,000 |  |
ATM Agreement [Member] | Maximum [Member] |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Common stock issuable and sellable under offering agreement |  |  |  | $ 75,000,000
Common Stock [Member] |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |
Sale of common stock in underwritten public offering | 14.2 |  |  |
Sale of common stock, public offering price | $ 16.25 |  |  |
Net proceeds from sale of shares, after deducting underwriting discounts and commissions and other estimated offering expenses | $ 215,800,000 |  |  |

X
- Definition Common stock capital shares value reserved for future issuance. + References No definition available. + Details
Name: | sgmo_CommonStockCapitalSharesValueReservedForFutureIssuance
Namespace Prefix: | sgmo_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Net proceeds from issuance public offering. + References No definition available. + Details
Name: | sgmo_NetProceedsFromIssuancePublicOffering
Namespace Prefix: | sgmo_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- 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

X
- Definition Per share or per unit amount of equity securities issued. + References No definition available. + Details
Name: | us-gaap_SharesIssuedPricePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- 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 http://asc.fasb.org/extlink&oid=6877327&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 http://asc.fasb.org/extlink&oid=109259400&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 http://asc.fasb.org/extlink&oid=27012166&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 http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |