v3.8.0.1
Organization and description of business (Additional Information) (Details)
$ / shares in Units, $ in Millions
1 Months Ended 12 Months Ended
Nov. 13, 2017
$ / shares
shares
Dec. 22, 2017
USD ($)
shares
Nov. 15, 2017
shares
Apr. 28, 2017
USD ($)
shares
Apr. 17, 2017
shares
Mar. 20, 2017
shares
Mar. 31, 2016
Dec. 28, 2015
USD ($)
Dec. 31, 2017
USD ($)
$ / shares
shares
Dec. 22, 2017
HKD ($)
Dec. 31, 2016
$ / shares
shares
Aug. 10, 2016
shares
Jan. 19, 2016
$ / shares
Noncontrolling Interest, Ownership Percentage by Parents               100.00%          
Payments to Acquire Businesses, Gross | $               $ 52,000,000 $ 11,000,000        
Business Combination Consideration Transferred             1,162,305 post-split shares consideration of $52 million in cash, plus up to 19.9% or 3.4 million newly issued ordinary shares (the Shares) of the Company          
Common Stock Shares Authorized                 50,000,000   50,000,000 12,500,000  
Common stock, par value | $ / shares $ 0.004               $ 0.004   $ 0.004    
Shares issued for secondary offering, shares 2,314,500   434,783   434,783 117,361              
Minimum [Member]                          
Common stock, par value | $ / shares                         $ 0.001
Maximum [Member]                          
Common stock, par value | $ / shares                         $ 0.004
Giant Connection Limited [Member]                          
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned   $ 2,400,000               $ 19.6      
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares   2,220,283                      
Hong Kong [Member]                          
Payments to Acquire Businesses, Gross | $       $ 32,600,000                  
Shares issued for secondary offering, shares       1,500,000