v3.21.2

Warrant derivative liability (Placement Agent Warrants) (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Apr. 05, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Nov. 15, 2017
Class of Warrant or Right, Outstanding					896,739
Fair Value Adjustment of Warrants		$ 4	$ 33	$ 394
Placement Agent Warrants [Member]
Warrants issued During Period	34,783
Percentage Of Shares Issue To Placement Agent	8.00%
Class of Warrant or Right, Exercise Price of Warrants or Rights					$ 1.00
Class of Warrant or Right, Outstanding		95,653	95,653		95,653
Warrants Not Settleable in Cash, Fair Value Disclosure		$ 46	$ 30

X

- Definition

Percentage of shares issued to placement agents.

+ References

No definition available.

+ Details

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

X

- Definition

Number of warrants issued during the period.

+ References

No definition available.

+ Details

Name:	sgoc_WarrantsIssuedDuringPeriod
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

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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

Amount of expense (income) related to adjustment to fair value of warrant liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section 25
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=109262497&loc=d3e20148-110875

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

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

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: