v2.4.1.9
Earnings per share (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Reconciliation of the basic and diluted earnings per share computation:      
Net (loss) income for earnings per share $ (2,288)us-gaap_NetIncomeLoss $ 8,444us-gaap_NetIncomeLoss $ 4,213us-gaap_NetIncomeLoss
Weighted average shares used in diluted computation - basic and diluted 17,406,069us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted 17,193,189us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted 17,059,575us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted
(Loss) Income per share - basic and diluted $ (0.13)us-gaap_EarningsPerShareBasicAndDiluted $ 0.49us-gaap_EarningsPerShareBasicAndDiluted $ 0.25us-gaap_EarningsPerShareBasicAndDiluted
Number of shares owned by sponsors that were no longer subject to cancellation and were included in the calculation of basic earnings per share computation 361,327sgoc_SharesOwnedBySponsorsNoLongerSubjectToCancellationIncludedInCalculationOfBasicEarningsPerShare 361,327sgoc_SharesOwnedBySponsorsNoLongerSubjectToCancellationIncludedInCalculationOfBasicEarningsPerShare  
Number of shares owned by sponsors remaining in escrow and were therefore not included in the calculation of basic earnings per share computation 405,495sgoc_SharesOwnedBySponsorsRemainingInEscrowNotIncludedInCalculationOfBasicEarningsPerShare 405,496sgoc_SharesOwnedBySponsorsRemainingInEscrowNotIncludedInCalculationOfBasicEarningsPerShare