Basis of Presentation - Reconciliation of Cash and Cash Equivalents to Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 3,473,066	$ 4,800,554	$ 3,618,305	$ 4,120,738
Merchant reserves	15,080,233	14,977,468	14,725,430	15,803,641
Total	$ 18,553,299	$ 19,778,022	$ 18,343,735	$ 19,924,379