v2.4.1.9
Warrant derivative liability (Underwriters warrants) (Details) (Underwriter Warrants [Member], USD $)
In Thousands, except Share data, unless otherwise specified
1 Months Ended 12 Months Ended
Dec. 23, 2010
Dec. 31, 2013
Dec. 31, 2011
Dec. 31, 2014
Dec. 31, 2012
Warrant Activity [Line Items]          
Option to purchase warrants, value $ 1sgoc_OptionToPurchaseWarrantsValue        
Number of ordianry shares available for purchase by warrants 66,667us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights        
Percetnage of total shares sold in the secondary offering 5.00%sgoc_ClassOfWarrantOrRightPercentageOfSharesSoldInOffering        
Percentage of the price of the shares sold in the secondary offering 120.00%sgoc_ClassOfWarrantOrRightPercentageOfSharesPriceInOffering        
Expiration date   Dec. 20, 2015      
Exercise price of warrant $ 6.00us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1        
Exercisable Date   Jun. 12, 2012      
Warrants repurchased     53,096sgoc_WarrantsRepurchased    
Warrants repurchased, value     27sgoc_WarrantsRepurchasedValue    
Warrants repurchased, price per share     $ 0.50sgoc_WarrantsRepurchasedPricePerShare    
Warrants outstanding   13,571us-gaap_ClassOfWarrantOrRightOutstanding   13,571us-gaap_ClassOfWarrantOrRightOutstanding 13,571us-gaap_ClassOfWarrantOrRightOutstanding
Warrants fair value   3sgoc_WarrantsFairValue   2sgoc_WarrantsFairValue  
American Binomial Option Valuation Model [Member]
         
Warrant Activity [Line Items]          
Estimated warrant exercise price       $ 6.00us-gaap_FairValueAssumptionsExercisePrice
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnderwriterWarrantsMember
/ us-gaap_ValuationTechniqueAxis
= sgoc_AmericanBinomialOptionValuationModelMember
 
Estimated warrant market price per share       $ 0.62sgoc_EstimatedWarrantMarketPricePerShare
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnderwriterWarrantsMember
/ us-gaap_ValuationTechniqueAxis
= sgoc_AmericanBinomialOptionValuationModelMember
 
Expected remaining term       1 year  
Expected volatility       176.00%us-gaap_FairValueAssumptionsExpectedVolatilityRate
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnderwriterWarrantsMember
/ us-gaap_ValuationTechniqueAxis
= sgoc_AmericanBinomialOptionValuationModelMember
 
Risk-free interest rate       0.11%us-gaap_FairValueAssumptionsRiskFreeInterestRate
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnderwriterWarrantsMember
/ us-gaap_ValuationTechniqueAxis
= sgoc_AmericanBinomialOptionValuationModelMember
 
Warrants fair value       2sgoc_WarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnderwriterWarrantsMember
/ us-gaap_ValuationTechniqueAxis
= sgoc_AmericanBinomialOptionValuationModelMember
 
Cox-Ross Rubinstein Binomial Model [Member]
         
Warrant Activity [Line Items]          
Estimated warrant exercise price       $ 6.00us-gaap_FairValueAssumptionsExercisePrice
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnderwriterWarrantsMember
/ us-gaap_ValuationTechniqueAxis
= sgoc_CoxRossRubinsteinBinomialModelMember
 
Estimated warrant market price per share       $ 0.62sgoc_EstimatedWarrantMarketPricePerShare
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnderwriterWarrantsMember
/ us-gaap_ValuationTechniqueAxis
= sgoc_CoxRossRubinsteinBinomialModelMember
 
Expected remaining term       1 year  
Expected volatility       176.00%us-gaap_FairValueAssumptionsExpectedVolatilityRate
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnderwriterWarrantsMember
/ us-gaap_ValuationTechniqueAxis
= sgoc_CoxRossRubinsteinBinomialModelMember
 
Risk-free interest rate       0.11%us-gaap_FairValueAssumptionsRiskFreeInterestRate
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnderwriterWarrantsMember
/ us-gaap_ValuationTechniqueAxis
= sgoc_CoxRossRubinsteinBinomialModelMember
 
Warrants fair value       $ 2sgoc_WarrantsFairValue
/ us-gaap_ClassOfWarrantOrRightAxis
= sgoc_UnderwriterWarrantsMember
/ us-gaap_ValuationTechniqueAxis
= sgoc_CoxRossRubinsteinBinomialModelMember