Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Realized gains or losses on investments	$ 0	$ 0	$ 0	$ 0
Net change in unrealized depreciation on investments	$ 1,052,185	$ (243,836)	9,730,903	1,903,180
Level 3 [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Net change in unrealized depreciation on investments			$ 9,730,903	$ 1,903,180