Commitments and Contingencies (Details Textual) - USD ($)	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Commitments and Contingencies (Textual)
Operating lease expense	$ 265,600	$ 270,008
Outstanding trade letters of credit	3,572,640		$ 6,546,920
Purchase commitment amount	$ 3,500,000

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

No definition available.

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration