XML 59 R41.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Marketable Securities - Additional Information (Detail) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Investments Debt And Equity Securities [Abstract] |  |  |
Investments maturity period | 2 years |  |
Realized losses | $ 0 | $ 0 | $ 0
Other-than-temporary impairments of available-for-sale securities | 0 | $ 0 | $ 0
Investments other-than-temporarily impaired | $ 0 |  |

X
- Definition Investments maturity dates available for sale securities. + References No definition available. + Details
Name: | sgmo_InvestmentsMaturityDatesAvailableForSaleSecurities
Namespace Prefix: | sgmo_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Other than temporarily impaired investment. + References No definition available. + Details
Name: | sgmo_OtherThanTemporarilyImpairedInvestment
Namespace Prefix: | sgmo_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount by which the fair value of an investment in debt and equity securities categorized as Available-for-sale is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 + Details
Name: | us-gaap_OtherThanTemporaryImpairmentLossesInvestmentsAvailableforsaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration