Quarterly report pursuant to Section 13 or 15(d)

Segment information (Details 3)

v3.7.0.1
Segment information (Details 3) - USD ($)
Jun. 30, 2017
Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]    
Accounts receivable $ 42,737,207 $ 46,280,769
China Mainland [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Accounts receivable 29,275,047 29,663,633
Asia, others [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Accounts receivable 10,496,258 10,441,358
Europe [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Accounts receivable 2,507,947 3,875,979
North America [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Accounts receivable 423,027 2,260,840
South America [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Accounts receivable 15,803 26,610
Africa [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Accounts receivable 378 378
Others [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Accounts receivable $ 18,747 $ 11,971