XML 43 R31.htm IDEA: XBRL DOCUMENT v3.19.1
Significant Accounting Policies - Schedule of Reconciliation of Cash and Cash Equivalents, and Restricted Cash Reported (Detail) - USD ($)
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Accounting Policies [Abstract]      
Cash and cash equivilents $ 745,240 $ 698,033  
Escrowed cash 1,880,231 263,558  
Total cash, cash equivalents, and escrowed cash shown in the statement of cash flows $ 2,625,471 $ 961,591 $ 1,244,051