Quarterly report pursuant to Section 13 or 15(d)

Certain Risks and Concentrations (Details)

v3.10.0.1
Certain Risks and Concentrations (Details)
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Major customers [Member] | A [Member]        
Concentration Risk [Line Items]        
Concentration risk, Percentage 20.00% [1] 22.00% [1]
Major customers [Member] | B [Member]        
Concentration Risk [Line Items]        
Concentration risk, Percentage 18.00% [1] 13.00% [1]
Major customers [Member] | C [Member]        
Concentration Risk [Line Items]        
Concentration risk, Percentage 13.00% 11.00% 13.00% [1]
Major customers [Member] | D [Member]        
Concentration Risk [Line Items]        
Concentration risk, Percentage 10.00% [1] 11.00% [1]
Major suppliers [Member] | A [Member]        
Concentration Risk [Line Items]        
Concentration risk, Percentage 47.00% [1] 32.00% [1]
Major suppliers [Member] | B [Member]        
Concentration Risk [Line Items]        
Concentration risk, Percentage 16.00% [1] 22.00% [1]
Major suppliers [Member] | C [Member]        
Concentration Risk [Line Items]        
Concentration risk, Percentage 12.00% [1] 15.00% [1]
Major suppliers [Member] | D [Member]        
Concentration Risk [Line Items]        
Concentration risk, Percentage [1] 10.00%
Major suppliers [Member] | E (Hai Yi Shipping Limited, a related party) [Member]        
Concentration Risk [Line Items]        
Concentration risk, Percentage [1] [1] [1] 11.00%
Major suppliers [Member] | F (Hong Fa Shipping Limited, a related party) [Member]        
Concentration Risk [Line Items]        
Concentration risk, Percentage [1] 42.00% [1] 40.00%
Major suppliers [Member] | G (Hong Long, a related party) [Member]        
Concentration Risk [Line Items]        
Concentration risk, Percentage [1] 38.00% [1] 31.00%
[1] less than 10%