XML 43 R31.htm IDEA: XBRL DOCUMENT v3.20.2
Trade Accounts and Bills Receivable, Net (Tables)
6 Months Ended
Jun. 30, 2020
Trade Accounts and Bills Receivable, net [Abstract]  
Schedule of trade accounts and bills receivable

   December 31,   June 30, 
   2019   2020 
Trade accounts receivable  $12,517,626   $16,464,428 
Less: Allowance for doubtful accounts   (4,650,686)   (5,009,230)
    7,866,940    11,455,198 
Bills receivable   85,480    92,261 
   $7,952,420   $11,547,459 

 

Schedule of analysis of the allowance for doubtful accounts

   June 30,   June 30, 
   2019   2020 
Balance at beginning of period  $3,657,173   $4,650,686 
Provision for the period   605,098    968,627 
Reversal - recoveries by cash   (281,160)   (540,925)
Charged to consolidated statements of operations and comprehensive (loss) income   323,938    427,702 
Foreign exchange adjustment   2,939    (69,158)
Balance at end of period  $3,984,050   $5,009,230