Basis of Presentation - Reconciliation of Cash and Cash Equivalents to Cash, Cash Equivalents and Merchant Reserves (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 4,465,718	$ 2,695,177	$ 3,473,066	$ 4,800,554
Merchant reserves	11,297,894	12,645,803	15,080,233	14,977,468
Total	$ 15,763,612	$ 15,340,980	$ 18,553,299	$ 19,778,022