Investment - Summary of Available-for-Sale Investments by Security type (Detail) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Net Investment Income [Line Items]
Amortized cost	$ 105,001,320	$ 64,929,745
Gross Unrealized Gains		9,505
Gross Unrealized Losses	(6,471)
Estimated Fair Value	104,994,849	64,939,250
U.S. Treasuries - ST [Member]
Net Investment Income [Line Items]
Amortized cost		4,999,587
Gross Unrealized Gains		7,463
Estimated Fair Value		5,007,050
U.S Treasury Bond Securities Cash Equivalents [Member]
Net Investment Income [Line Items]
Amortized cost	94,993,295	59,930,158
Gross Unrealized Gains		2,042
Gross Unrealized Losses	(1,195)
Estimated Fair Value	94,992,100	$ 59,932,200
Bond Funds – ST [Member]
Net Investment Income [Line Items]
Amortized cost	10,008,025
Gross Unrealized Losses	(5,276)
Estimated Fair Value	$ 10,002,749