v3.21.2

Organization and description of business (Acquisition of Paris Sky Limited) (Details) $ / shares in Units, $ in Thousands |  | 12 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Jun. 07, 2018 HKD ($) shares | Jun. 07, 2018 USD ($) shares | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Jan. 31, 2020 | Jun. 26, 2018 USD ($) | Jun. 25, 2018 USD ($) | Jun. 07, 2018 USD ($) $ / shares | Apr. 18, 2018
Share Capital Authorized Value |  |  |  |  |  |  | $ 2,010,000 | $ 201,000 |  |
Debt Instrument, Interest Rate, Stated Percentage |  |  |  |  |  | 8.00% |  |  |  | 2.50%
Stock Issued During Period, Value, Acquisitions |  |  | $ 14,660,000 | $ 5,242,000 | $ 8,188,000 |  |  |  |  |
Paris Sky Limited |  |  |  |  |  |  |  |  |  |
Fair value of equity issued in business acquisition |  |  |  |  |  |  |  |  | $ 4,780,000 |
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned | $ 30,330 |  |  |  |  |  |  |  | $ 3,890,000 |
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares | 3,889,050 | 3,889,050 |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, Acquisitions | shares | 3,889,050 | 3,889,050 |  |  |  |  |  |  |  |
Business Combination, Consideration Transferred |  | $ 48,128,000 |  |  |  |  |  |  |  |
Sale of Stock, Price Per Share | $ / shares |  |  |  |  |  |  |  |  | $ 1.23 |
Business Acquisition, Percentage of Voting Interests Acquired | 100.00% |  |  |  |  |  |  |  | 100.00% |
Debt Instrument, Face Amount | $ 27,100 |  |  |  |  |  |  |  | $ 3,470,000 |
Debt Instrument, Interest Rate, Stated Percentage | 8.00% |  |  |  |  |  |  |  | 8.00% |
Stock Issued During Period, Value, Acquisitions |  | $ 4,780,000 |  |  |  |  |  |  |  |
Paris Sky Limited | Century Skyway Limited |  |  |  |  |  |  |  |  |  |
Percentage of ownership used to pay to acquiree in business combination | 49.00% | 49.00% |  |  |  |  |  |  |  |
Fair value of portion of ownership being used to pay acquiree in business combination | $ 126,130 | $ 16,170,000 |  |  |  |  |  |  |  |
Paris Sky Limited | Boca International Limited |  |  |  |  |  |  |  |  |  |
Percentage of ownership used to pay to acquiree in business combination | 49.00% | 49.00% |  |  |  |  |  |  |  |
Fair value of portion of ownership being used to pay acquiree in business combination | $ 184,840 | $ 23,700,000 |  |  |  |  |  |  |  |
Paris Sky Limited | Giant Connection Limited |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount | $ 27,100 |  |  |  |  |  |  |  | $ 3,470,000 |
Debt Instrument, Interest Rate, Stated Percentage | 8.00% |  |  |  |  |  |  |  | 8.00% |

X
- Definition Fair value of portion of ownership being used to pay acquiree in business combination. + References No definition available. + Details
Name: | sgoc_FairValueOfPortionOfOwnershipToUseToPayAcquireeInBusinessCombination
Namespace Prefix: | sgoc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of ownership is used to pay to acquiree in business combination. + References No definition available. + Details
Name: | sgoc_PercentageOfOwnershipUsedToPayToAcquireeInBusinessCombination
Namespace Prefix: | sgoc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount represents authorized value of share capital. + References No definition available. + Details
Name: | sgoc_ShareCapitalAuthorizedValue
Namespace Prefix: | sgoc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Value of equity interests (such as common shares, preferred shares, or partnership interest) issued or issuable to acquire the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b)(4) -URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479 + Details
Name: | us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of shares of equity interests issued or issuable to acquire entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b)(4) -URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479 + Details
Name: | us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of voting equity interests acquired at the acquisition date in the business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463 + Details
Name: | us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6613-128477 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6578-128477 + Details
Name: | us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + 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 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair value of equity issued in a business combination. + 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_EquityIssuedInBusinessCombinationFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- 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: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares of stock issued during the period pursuant to acquisitions. + 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 S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770 Reference 3: 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_StockIssuedDuringPeriodSharesAcquisitions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value of stock issued pursuant to acquisitions during the period. + 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 http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 2: 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 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29-31) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodValueAcquisitions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=sgoc_ParisSkyLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=sgoc_CenturySkywayLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=sgoc_BocaInternationalLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=sgoc_GiantConnectionLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |