v3.21.2

Warrant derivative liability (Investor Warrants) (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 18, 2020	Apr. 05, 2017	Dec. 31, 2020	Dec. 31, 2019	Nov. 15, 2017	Nov. 13, 2017
Class of Warrant or Right, Outstanding					896,739
Private Placement [Member] | Investor [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights					$ 1.00	$ 0.80
Class of Warrant or Right, Outstanding			422,922	721,836
Warrants Not Settleable in Cash, Fair Value Disclosure			$ 203	$ 223
Securities Purchase Agreement [Member]
Stock Issued During Period, Shares, New Issues	4,500,000	434,783
Warrant Purchase on Issue of Ordinary Shares		326,087
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 2.75
Securities Purchase Agreement, Warrants Issued percentage		75.00%

X

- Definition

Represents the percentage of warrants issued in the securities purchase agreement.

+ References

No definition available.

+ Details

Name:	sgoc_SecuritiesPurchaseAgreementWarrantsIssuedPercentage
Namespace Prefix:	sgoc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

It represents the number of warrant purchase on issue of share.

+ References

No definition available.

+ Details

Name:	sgoc_WarrantPurchaseOnIssueOfOrdinaryShares
Namespace Prefix:	sgoc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of warrants or rights outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_ClassOfWarrantOrRightOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
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=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 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=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 http://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

X

- Definition

Fair value portion of warrants not settleable in cash classified as equity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

Name:	us-gaap_WarrantsNotSettleableInCashFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

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

X

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_InvestorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	sgoc_AgreementTypeAxis=sgoc_SecuritiesPurchaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: