Annual report pursuant to Section 13 and 15(d)

Restricted Cash - Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details)

v3.19.1
Restricted Cash - Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($)
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Restricted Cash and Investments [Abstract]      
Cash and cash equivalents $ 11,376,373 $ 18,529,757  
Restricted cash 25,980 102,027  
Cash, cash equivalents and restricted cash shown in the consolidated statement of cash flows $ 11,402,353 $ 18,631,784 $ 20,772,689