Fair Value Measurements - Summary of Quantitative Information of Fair Value Measurements of Investments (Detail)		Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value		$ 330,593,500	$ 340,298,376
Senior Secured Trade Finance Participations [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	[1]	67,795,496	71,606,458
Senior Secured Term Loan Participations [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	[1]	158,424,908	180,500,425
Equity Warrants [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value		1,199,618	1,080,222
Other Investments [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value		3,758,063
Senior Secured Term Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	[1]	99,415,415	83,353,208
Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value		$ 330,593,500	340,298,376
Valuation technique		us-gaap:IncomeApproachValuationTechniqueMember
Level 3 [Member] | Senior Secured Trade Finance Participations [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value		$ 67,795,496	71,606,458
Level 3 [Member] | Senior Secured Trade Finance Participations [Member] | Income Approach (DCF) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	[2]	$ 67,136,562	$ 70,792,700
Level 3 [Member] | Senior Secured Trade Finance Participations [Member] | Income Approach (DCF) [Member] | Minimum [Member] | Market yield [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range (weighted average)	[2]	9.0	9.0
Level 3 [Member] | Senior Secured Trade Finance Participations [Member] | Income Approach (DCF) [Member] | Maximum [Member] | Market yield [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range (weighted average)	[2]	16.4	16.8
Level 3 [Member] | Senior Secured Trade Finance Participations [Member] | Income Approach (DCF) [Member] | Weighted Average [Member] | Market yield [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range (weighted average)	[2]	11.7	12.7
Level 3 [Member] | Senior Secured Trade Finance Participations [Member] | Collateral Based Approach [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	[3]	$ 658,934	$ 813,758
Level 3 [Member] | Senior Secured Trade Finance Participations [Member] | Collateral Based Approach [Member] | Minimum [Member] | Measurement Input Value Of Collateral
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range (weighted average)	[3]	1.0	1.0
Level 3 [Member] | Senior Secured Trade Finance Participations [Member] | Collateral Based Approach [Member] | Maximum [Member] | Measurement Input Value Of Collateral
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range (weighted average)	[3]	1.1	1.1
Level 3 [Member] | Senior Secured Term Loan Participations [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value		$ 158,424,908	$ 180,500,425
Valuation technique		us-gaap:IncomeApproachValuationTechniqueMember	us-gaap:IncomeApproachValuationTechniqueMember
Level 3 [Member] | Senior Secured Term Loan Participations [Member] | Minimum [Member] | Market yield [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range (weighted average)		11.5	11.0
Level 3 [Member] | Senior Secured Term Loan Participations [Member] | Maximum [Member] | Market yield [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range (weighted average)		15.0	15.9
Level 3 [Member] | Senior Secured Term Loan Participations [Member] | Weighted Average [Member] | Market yield [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range (weighted average)		12.7	13.0
Level 3 [Member] | Equity Warrants [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value		$ 1,199,618	$ 1,080,222
Valuation technique		us-gaap:ValuationTechniqueOptionPricingModelMember	us-gaap:ValuationTechniqueOptionPricingModelMember
Level 3 [Member] | Other Investments [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	[4]	$ 3,758,063	$ 3,758,063
Valuation technique		trilinc:HybridIncomeAndCollateralBasedApproachMember	trilinc:HybridIncomeAndCollateralBasedApproachMember
Level 3 [Member] | Other Investments [Member] | Weighted Average [Member] | Market yield [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range (weighted average)	[4]	8.80	8.75
Level 3 [Member] | Senior Secured Term Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value		$ 99,415,415	$ 83,353,208
Valuation technique			us-gaap:IncomeApproachValuationTechniqueMember
Level 3 [Member] | Senior Secured Term Loans [Member] | Minimum [Member] | Market yield [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range (weighted average)		11.0	10.0
Level 3 [Member] | Senior Secured Term Loans [Member] | Maximum [Member] | Market yield [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range (weighted average)		14.5	14.5
Level 3 [Member] | Senior Secured Term Loans [Member] | Weighted Average [Member] | Market yield [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Range (weighted average)		12.4	12.4

[1] Refer to Notes 2, 3 and 4 of the consolidated financial statements for additional information on the Company’s investments.

[2] The Company used the income approach for Algodonera, FRIAR, CAGSA, and Functional and a hybrid of the collateral based approach and the income approach for Sancor and Mac Z, using additional unobservable inputs including recovery rates ranging from 15% to 30%, after considering potential and ongoing litigation and expected collection period ranging from 2 to 3 years. See Note 3 “Watch List Investments” for further information.

[3] Collateral based approach used for the following watch list investments: Profasa and GPI. See Note 3 “Watch List Investments” for further information.

[4] Receivable from IIG TOF B.V. using additional discount rate of 20%.