v3.8.0.1
Acquisition of subsidiary and deposits paid for acquisition of subsidiaries (Additional Information) (Details)
$ / shares in Units, $ in Thousands, $ in Millions
 1 Months Ended 12 Months Ended
Mar. 15, 2016
shares
Dec. 22, 2017
USD ($)
shares
Dec. 22, 2017
HKD ($)
shares
Apr. 28, 2017
USD ($)
shares
Dec. 31, 2016
USD ($)
Dec. 27, 2016
USD ($)
Dec. 31, 2015
USD ($)
Dec. 28, 2015
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Dec. 26, 2017
$ / shares
Nov. 13, 2017
$ / shares
May 10, 2017
USD ($)
Sep. 19, 2016
$ / shares
Mar. 31, 2016
USD ($)
Mar. 07, 2016
$ / shares
Dec. 22, 2015
USD ($)
Business Acquisition [Line Items]                                  
Shares issued for acquisition | shares 1,162,305     1,500,000                          
Fair value of shares issued | $ / shares                       $ 0.80   $ 3.30      
Cash               $ 52,000 $ 11,000                
Goodwill         $ 36,504   $ 0   49,977 $ 36,504              
Stock Issued During Period, Value, Acquisitions       $ 32,600         $ 4,679 4,080              
Stock Issued During Period, Shares, Acquisitions | shares 1,162,305     1,500,000                          
Boca International Limited [Member]                                  
Business Acquisition [Line Items]                                  
Maximum percentage of new shares company offered as consideration for acquisition             19.90%                    
Fair value of shares issued | $ / shares                               $ 3.51  
Cash             $ 52,000                    
Goodwill               $ 36,504             $ 36,504    
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents                             1    
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt                             $ 332    
Business Combination, Consideration Transferred             56,080                    
Sola Green Technologies Limited [Member]                                  
Business Acquisition [Line Items]                                  
Cash             $ 34,000                    
Total purchase price agreed to in the form of cash or ordinary shares                                 $ 40,000
Century Skyway Limited [Member]                                  
Business Acquisition [Line Items]                                  
Cash         32,600 $ 35,000                      
Total purchase price agreed to in the form of cash or ordinary shares         32,000         $ 32,000              
Goodwill                                
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents                         1        
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt                         $ 68        
Business Combination, Consideration Transferred         $ 34,925                        
Giant Connection Limited [Member]                                  
Business Acquisition [Line Items]                                  
Shares issued for acquisition | shares   2,220,283 2,220,283                            
Goodwill   $ 248                              
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents   943                              
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets Loans Receivables   670                              
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets Interest Receivables   6                              
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment   508                              
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities, Current   14                              
Business Combination, Consideration Transferred   $ 2,354 $ 19.6                            
Stock Issued During Period, Shares, Acquisitions | shares   2,220,283 2,220,283                            
Business Acquisition, Share Price | $ / shares                     $ 1.06