Basis of Presentation - Reconciliation of Cash and Cash Equivalents to Cash, Cash Equivalents and Merchant Reserves (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 3,276,511	$ 2,695,177	$ 2,722,357	$ 4,800,554
Merchant reserves	11,074,891	12,645,803	14,782,305	14,977,468
Total	$ 14,351,402	$ 15,340,980	$ 17,504,662	$ 19,778,022