Significant Accounting Policies - Additional Information (Detail)		3 Months Ended		6 Months Ended		12 Months Ended		68 Months Ended
		Jun. 30, 2019 USD ($) Company Investment $ / shares	Jun. 30, 2018 USD ($) $ / shares	Jun. 30, 2019 USD ($) Company Investment Loans $ / shares	Jun. 30, 2018 USD ($) $ / shares	Dec. 31, 2018 USD ($) Company Investment $ / shares	Dec. 31, 2017 USD ($) $ / shares	Dec. 31, 2017 USD ($) $ / shares
Significant Accounting Policies [Line Items]
Due date for unpaid principal and interest				90 days
Fair Value		$ 366,279,562		$ 366,279,562		$ 372,977,743
Percentage of investment in loans				100.00%		100.00%
Number of companies on non-accrual status | Company		7		7		6
Unrecorded investment interest income		$ 11,062,607	$ 12,103,857	$ 22,342,110	$ 22,231,043
Minimum investment maturity period				12 months
Paid-in-kind interest		2,232,871	$ 1,015,742	$ 3,902,348	$ 1,864,364
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 assets value per unit | $ / shares		$ 8.134		$ 8.134		$ 8.227
Net asset value per unit | $ / shares		$ 8.11	$ 8.31	$ 8.11	$ 8.31	$ 8.20	$ 8.42	$ 8.42
Investment, unrealized depreciation		$ 1,900,000		$ 1,900,000		$ 8,100,000
Organization and offering expenses				4.70%
Amount paid to the sponsor due to reimbursement hurdle		$ 0	$ 387,000		$ 387,000
Number of watch list investments | Investment		11		11		12
Number of companies included in investment portfolio | Company		45		45
Largest Loan by Value [Member]
Significant Accounting Policies [Line Items]
Fair Value		$ 22,962,153		$ 22,962,153
Number of investment loans | Loans				5
Investment Concentration [Member]
Significant Accounting Policies [Line Items]
Fair Value		$ 280,857,000		$ 280,857,000
Minimum investment maturity period				12 months
Percentage of Investment				76.90%
Investment Concentration [Member] | Investment Portfolio [Member]
Significant Accounting Policies [Line Items]
Percentage of Investment				74.50%
Investment Concentration [Member] | Investment Portfolio [Member] | Largest Loan by Value [Member]
Significant Accounting Policies [Line Items]
Percentage of Investment				6.30%
Investment Concentration [Member] | Investment Portfolio [Member] | Five Largest Loans by Value [Member]
Significant Accounting Policies [Line Items]
Percentage of Investment				26.80%
IIG [Member] | Sub-advisory Agreement [Member]
Significant Accounting Policies [Line Items]
Number of watch list investments | Investment		7		7
Misapplication of investments							$ 6,000,000
Valuation of Investments [Member]
Significant Accounting Policies [Line Items]
Prior period adjustments				$ 871,000
Net Change In Unrealized Depreciation On Investments [Member]
Significant Accounting Policies [Line Items]
Prior period adjustments				702,000
Net Increase In Net Assets [Member]
Significant Accounting Policies [Line Items]
Prior period adjustments				$ (702,000)
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	$ 12,420,600
Related party transaction reimbursement amounts paid							4,240,200	4,240,200
Remaining excess amount payment percentage				50.00%
Amount paid to the sponsor due to reimbursement hurdle		$ 0	$ 387,000
Remaining aggregate balance due to affiliate		16,273,800		$ 16,273,800			$ 16,660,800	$ 16,660,800
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		$ 593,000		593,000
Reimbursement, aggregate amount of organization and offering costs incurred by Sponsor				$ 86,784
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				2015
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		$ 867,000		$ 867,000
Net assets value per unit | $ / shares		$ 8.134	$ 8.351	$ 8.134	$ 8.351	$ 8.227
Decrease in net asset value per unit | $ / shares			0.217		0.217	0.093
Class I Units [Member]
Significant Accounting Policies [Line Items]
Unpaid dealer manager fee		$ 42,000		$ 42,000
Net assets value per unit | $ / shares		$ 8.134	8.351	$ 8.134	8.351	8.227
Decrease in net asset value per unit | $ / shares			0.217		0.217	0.093
Class W Units [Member]
Significant Accounting Policies [Line Items]
Unpaid dealer manager and service fees		$ 2,000		$ 2,000
Net assets value per unit | $ / shares		$ 8.134	8.351	$ 8.134	8.351	8.227
Decrease in net asset value per unit | $ / shares			0.217		0.217	0.093
Class C Units, Class I Units and Class W Units [Member]
Significant Accounting Policies [Line Items]
Distribution, dealer manager and service fees payable		$ 911,000		$ 911,000
Class A Units [Member]
Significant Accounting Policies [Line Items]
Net assets value per unit | $ / shares		$ 8.134	8.351	$ 8.134	8.351	8.227
Decrease in net asset value per unit | $ / shares			0.217		0.217	0.093
Class Y Units [Member]
Significant Accounting Policies [Line Items]
Net assets value per unit | $ / shares		8.134	8.351	8.134	8.351	8.227
Decrease in net asset value per unit | $ / shares			0.217		0.217	0.093
Class Z Units [Member]
Significant Accounting Policies [Line Items]
Net assets value per unit | $ / shares		$ 8.134	8.351	$ 8.134	8.351	8.227
Decrease in net asset value per unit | $ / shares			$ 0.217		$ 0.217	$ 0.093
Non-Accrual Status [Member]
Significant Accounting Policies [Line Items]
Fair Value		$ 32,482,047		$ 32,482,047		$ 30,562,415
Percentage of investment in loans				8.90%		8.20%
Unrecorded investment interest income		1,127,675	$ 528,276	$ 2,242,958	$ 1,050,747
Senior Secured Term Loans [Member]
Significant Accounting Policies [Line Items]
Fair Value	[1]	84,349,839		$ 84,349,839		$ 88,858,707
Percentage of investment in loans				23.00%		23.80%
Senior Secured Term Loan Participations [Member]
Significant Accounting Policies [Line Items]
Fair Value	[1]	198,029,550		$ 198,029,550		$ 189,157,819
Percentage of investment in loans				54.10%		50.70%
Senior Secured Trade Finance Participations [Member]
Significant Accounting Policies [Line Items]
Fair Value	[1]	74,886,023		$ 74,886,023		$ 80,236,312
Percentage of investment in loans				20.40%		21.50%
Short Term Note [Member]
Significant Accounting Policies [Line Items]
Fair Value		$ 7,933,928		$ 7,933,928
Percentage of investment in loans				2.20%
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%

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