v2.4.1.9
Warrant derivative liability (Unit options) (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
1 Months Ended 12 Months Ended
Mar. 31, 2008
Dec. 31, 2013
Dec. 31, 2014
Dec. 31, 2012
Unit Options [Member]        
Warrant Activity [Line Items]        
Granted units 280,000sgoc_UnitOptionsGranted
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnitOptionsMember
     
Per unit selling price $ 10.00us-gaap_SharesIssuedPricePerShare
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnitOptionsMember
     
Warrants outstanding   280,000us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnitOptionsMember
[1]    [1] 280,000us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnitOptionsMember
[1]
Exercise price of warrant   $ 9.98us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnitOptionsMember
   
Market price per share   $ 0sgoc_QuotedMarketPricePerShare
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnitOptionsMember
   
Estimated warrant value   $ 6sgoc_EstimatedWarrantValue
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnitOptionsMember
   
Estimated warrant value per share   0.02sgoc_EstimatedWarrantValuePerShare
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnitOptionsMember
   
Estimated warrant exercise price   $ 3.39us-gaap_FairValueAssumptionsExercisePrice
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnitOptionsMember
   
Expected remaining term   3 months    
Expected volatility   30.00%us-gaap_FairValueAssumptionsExpectedVolatilityRate
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnitOptionsMember
   
Risk-free interest rate   0.05%us-gaap_FairValueAssumptionsRiskFreeInterestRate
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnitOptionsMember
   
Representative Warrants [Member]        
Warrant Activity [Line Items]        
Exercise price of warrant $ 8.00us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_RepresentativeWarrantsMember
     
Expiration date Mar. 07, 2014      
[1] Each unit option included one ordinary share and one ordinary share warrant.