Significant Accounting Policies - Additional Information (Detail)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020 USD ($) Company Investment $ / shares	Jun. 30, 2019 USD ($) $ / shares	Jun. 30, 2020 USD ($) Company Investment Loans $ / shares	Jun. 30, 2019 USD ($) $ / shares	Dec. 31, 2019 USD ($) Company Investment $ / shares	Dec. 31, 2017 USD ($)	Mar. 31, 2020 $ / shares	Dec. 31, 2018 $ / shares
Significant Accounting Policies [Line Items]
Fair Value	$ 330,593,500		$ 330,593,500		$ 340,298,376
Percentage of investment in loans			100.00%		100.00%
Number of companies on non-accrual status | Company	7		7		10
Minimum investment maturity period			12 months
Paid-in-kind interest	$ 3,819,869	$ 2,232,871	$ 5,852,692	$ 3,902,348
Percentage of total selling compensation equaling of gross proceeds from offering			10.00%
Dealer manager fee payable period, maximum			5 years
Service fee payable period, maximum			6 years
Tax liability for uncertain tax provision	$ 0		$ 0
Interest and penalties related to unrecognized tax benefits			$ 0
Net asset value per unit | $ / shares	$ 7.759	$ 8.12	$ 7.759	$ 8.12	$ 8.01		$ 7.804	$ 8.20
Investment, unrealized depreciation	$ 9,700,000		$ 9,700,000
Organization and offering expenses			4.70%
Number of watch list investments | Investment	18		18		13
Largest Loan by Value [Member]
Significant Accounting Policies [Line Items]
Fair Value	$ 26,538,921		$ 26,538,921
Number of investment loans | Loans			5
Investment Concentration [Member] | Investment Portfolio [Member]
Significant Accounting Policies [Line Items]
Percentage of Investment			68.40%
Investment Concentration [Member] | Investment Portfolio [Member] | Largest Loan by Value [Member]
Significant Accounting Policies [Line Items]
Percentage of Investment			8.00%
Investment Concentration [Member] | Investment Portfolio [Member] | Five Largest Loans by Value [Member]
Significant Accounting Policies [Line Items]
Percentage of Investment			29.50%
IIG [Member] | Sub-advisory Agreement [Member]
Significant Accounting Policies [Line Items]
Fair Value	$ 29,197,409		$ 29,197,409
Number of watch list investments | Investment	7		7
Misapplication of investments					$ 6,000,000	$ 6,000,000
Maximum [Member]
Significant Accounting Policies [Line Items]
Organization and offering reimbursement limit			15.00%
TriLinc Global, LLC [Member] | Responsibility Agreement [Member]
Significant Accounting Policies [Line Items]
Expenses paid by the sponsor on behalf of company						12,420,600
Related party transaction reimbursement amounts paid						$ 4,057,734
Remaining excess amount payment percentage			50.00%
Related party transaction expenses	$ 0	$ 0
Due to affiliates	16,273,800		$ 16,273,800
TriLinc Global, LLC [Member] | Private Placement [Member]
Significant Accounting Policies [Line Items]
Organization and offering costs incurred by the Sponsor on behalf of the company	$ 596,000		596,000
Reimbursement, aggregate amount of organization and offering costs incurred by Sponsor			$ 87,159
TriLinc Global, LLC [Member] | Organization And Offering Costs [Member]
Significant Accounting Policies [Line Items]
Intercompany agreement description			Organization and offering costs incurred in connection with the Offering are reimbursable to the Sponsor to the extent the aggregate of selling commissions, dealer manager fees and other organization and offering costs do not exceed 15.0% of the gross offering proceeds (the “O&O Reimbursement Limit”) raised from the Offering and will be accrued and payable by the Company only to the extent that such costs do not exceed the O&O Reimbursement Limit.
Earliest tax year [Member]
Significant Accounting Policies [Line Items]
Open tax year			2016
Class C Units [Member]
Significant Accounting Policies [Line Items]
Distribution fee per annum percentage of estimated value per share	0.80%		0.80%
Distribution fee payable	$ 467,000		$ 467,000
Net assets value per unit | $ / shares	$ 7.769		$ 7.769		$ 8.024
Decrease in net asset value per unit | $ / shares			$ 0.255
Class I Units [Member]
Significant Accounting Policies [Line Items]
Unpaid dealer manager fee	$ 21,000		$ 21,000
Net assets value per unit | $ / shares	$ 7.769		$ 7.769		8.024
Decrease in net asset value per unit | $ / shares			$ 0.255
Class W Units [Member]
Significant Accounting Policies [Line Items]
Unpaid dealer manager and service fees	$ 1,000		$ 1,000
Net assets value per unit | $ / shares	$ 7.769		$ 7.769		8.024
Decrease in net asset value per unit | $ / shares			$ 0.255
Class C Units, Class I Units and Class W Units [Member]
Significant Accounting Policies [Line Items]
Distribution, dealer manager and service fees payable	$ 489,000		$ 489,000
Class A Units [Member]
Significant Accounting Policies [Line Items]
Net assets value per unit | $ / shares	$ 7.769		$ 7.769		8.024
Decrease in net asset value per unit | $ / shares			0.255
Class Y Units [Member]
Significant Accounting Policies [Line Items]
Net assets value per unit | $ / shares	7.769		7.769		8.024
Decrease in net asset value per unit | $ / shares			0.255
Class Z Units [Member]
Significant Accounting Policies [Line Items]
Net assets value per unit | $ / shares	$ 7.769		7.769		$ 8.024
Decrease in net asset value per unit | $ / shares			$ 0.255
Non-Accrual Status [Member]
Significant Accounting Policies [Line Items]
Fair Value	$ 15,944,282		$ 15,944,282		$ 38,261,499
Percentage of investment in loans			4.80%		11.20%
Unrecorded investment interest income	$ 652,107	$ 1,127,675	$ 2,007,809	$ 2,242,958
TGIF-A [Member]
Significant Accounting Policies [Line Items]
Percentage of each subsidiary ownership			100.00%
TGIF-TF [Member]
Significant Accounting Policies [Line Items]
Percentage of each subsidiary ownership			100.00%
TAI [Member]
Significant Accounting Policies [Line Items]
Percentage of each subsidiary ownership			100.00%
TGIF-LA [Member]
Significant Accounting Policies [Line Items]
Percentage of each subsidiary ownership			100.00%
TGIF-ATF [Member]
Significant Accounting Policies [Line Items]
Percentage of each subsidiary ownership			100.00%