Investment - Estimated Fair Values of Available for Sale Securities (Detail) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Estimated Fair Value	$ 104,994,849	$ 64,939,250

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

No definition available.

Name:	us-gaap_AvailableForSaleSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant