Investments - Schedule of Watch List Investments (Detail) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Schedule of Investments [Line Items]
Fair Value	$ 330,593,500	$ 340,298,376
Interest receivable	23,957,270	$ 16,501,872
Sub-advisory Agreement [Member] \| IIG [Member]
Schedule of Investments [Line Items]
Principal Amount	41,708,487
Fair Value	29,197,409
Interest receivable	2,770,705
Sub-advisory Agreement [Member] \| IIG [Member] \| Procesos Fabriles S.A. [Member] \| Collateral Based Approach [Member]
Schedule of Investments [Line Items]
Principal Amount	881,800
Fair Value	10,504
Sub-advisory Agreement [Member] \| IIG [Member] \| Algodonera Avellaneda S.A [Member] \| Income Approach [Member]
Schedule of Investments [Line Items]
Principal Amount	6,000,000
Fair Value	3,398,558
Interest receivable	778,500
Sub-advisory Agreement [Member] \| IIG [Member] \| IIG TOF B.V. [Member] \| Income Approach [Member]
Schedule of Investments [Line Items]
Principal Amount	6,000,000
Fair Value	3,758,063
Interest receivable	572,000
Sub-advisory Agreement [Member] \| IIG [Member] \| Frigorifico Regional Industrias Alimentarias S.A. Sucursal Uruguay [Member] \| Income Approach [Member]
Schedule of Investments [Line Items]
Principal Amount	9,000,000
Fair Value	6,361,679
Interest receivable	264,500
Sub-advisory Agreement [Member] \| IIG [Member] \| Compania Argentina de Granos S.A. [Member] \| Income Approach [Member]
Schedule of Investments [Line Items]
Principal Amount	12,500,000
Fair Value	9,679,636
Interest receivable	330,191
Sub-advisory Agreement [Member] \| IIG [Member] \| Sancor Cooperativas Unidas Ltda [Member] \| Hybrid Income and Collateral Based Approach [Member]
Schedule of Investments [Line Items]
Principal Amount	6,000,000
Fair Value	4,719,383
Interest receivable	604,633
Sub-advisory Agreement [Member] \| IIG [Member] \| Functional Products Trading S.A [Member] \| Income Approach [Member]
Schedule of Investments [Line Items]
Principal Amount	1,326,687
Fair Value	1,269,586
Interest receivable	$ 220,881

Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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