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 | ||||||||||||