SUMMARY OF CRITICAL ACCOUNTING POLICIES AND ESTIMATES - Summary of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Cash and cash equivalents	$ 1,676,808	$ 1,249,831	$ 52,876
Restricted cash	100,000	1,600,000	0
Cash and cash equivalents and restricted cash as shown in the consolidated statements of cash flows	$ 1,776,808	$ 2,849,831	$ 52,876	$ 1,105,787