Related Party Transactions - Management and Incentive Fee Compensation to Adviser (Details)	9 Months Ended
Sep. 30, 2022	Dec. 23, 2020	Sep. 30, 2017
Related Party Transactions [Abstract]
Property Management Fee, Percent Fee	2.00%
Management Fee, Description	The base management fee was calculated at an annual rate of 2.0% of Terra BDC’s average gross assets. The base management fee was payable quarterly in arrears and calculated based on the average value of Terra BDC’s gross assets at the end of the two most recently completed calendar quarters.
Incentive Fee, Description	The incentive fee consists of two parts. The first part, which was referred to as the subordinated incentive fee on income, was calculated and payable quarterly in arrears based upon Terra BDC’s “pre-incentive fee net investment income” for the immediately preceding quarter. The subordinated incentive fee on income was subject to a quarterly hurdle rate, expressed as a rate of return on adjusted capital at the beginning of the most recently completed calendar quarter, of 2.0% (8.0% annualized), subject to a “catch-up” feature. For this purpose, “pre-incentive fee net investment income” meant interest income, dividend income and any other income (including any other fees, other than fees for providing managerial assistance, such as commitment, origination, structuring, diligence and consulting fees or other fees that Terra BDC received from portfolio companies) accrued during the calendar quarter, minus Terra BDC’s operating expenses for the quarter (including the base management fee, expenses reimbursed to Terra Income Advisors under the Investment Advisory Agreement and any interest expense and dividends paid on any issued and outstanding preferred stock, but excluding the incentive fee). Pre-incentive fee net investment income includes, in the case of investments with a deferred interest feature (such as original issue discount, debt instruments with PIK interest and zero-coupon securities), accrued income that the Company has not yet received in cash. Pre-incentive fee net investment income did not include any realized capital gains, realized capital losses or unrealized capital appreciation or depreciation. The calculation of the subordinated incentive fee on income for each quarter was as follows:•No incentive fee was payable to Terra Income Advisors in any calendar quarter in which Terra BDC’s pre-incentive fee net investment income does not exceed the hurdle rate of 2.0% (8.0% annualized);•100% of Terra BDC’s pre-incentive fee net investment income, if any, that exceeded the hurdle rate but was less than or equal to 2.5% in any calendar quarter (10.0% annualized) was payable to Terra Income Advisors, all or any portion of which may be waived or deferred in Terra Income Advisors’s discretion. This portion of the pre-incentive fee net investment income (which exceeds the hurdle rate but is less than or equal to 2.5%) was referred to as the “catch-up.” The catch-up provision was intended to provide Terra Income Advisors with an incentive fee of 20.0% on all of Terra BDC’s pre-incentive fee net investment income when Terra BDC’s pre-incentive fee net investment income reaches 2.5% in any calendar quarter; and•20.0% of the amount of Terra BDC’s pre-incentive fee net investment income, if any, that exceeded 2.5% in any calendar quarter (10.0% annualized) was payable to Terra Income Advisors once the hurdle rate was reached and the catch-up was achieved. The second part of the incentive fee, which was referred to as the incentive fee on capital gains, was an incentive fee on capital gains earned on liquidated investments from the portfolio and was determined and payable in arrears as of the end of each calendar year (or upon termination of the Investment Advisory Agreement). This fee equaled 20.0% of Terra BDC’s incentive fee on capital gains, which equaled the realized capital gains on a cumulative basis from inception, calculated as of the end of the applicable period, computed net of all realized capital losses and unrealized capital depreciation on a cumulative basis, less the aggregate amount of any previously paid capital gains incentive fees. On a quarterly basis, Terra BDC accrued (but did not pay) for the unrealized capital gains incentive fee by calculating such fee as if it were due and payable as of the end of such period.
Servicing Fee Percent		0.75%	1.125%

Related Party Transactions - Management and Incentive Fee Compensation to Adviser (Details)

9 Months Ended

Sep. 30, 2022

Dec. 23, 2020

Sep. 30, 2017

2.00%

The base management fee was calculated at an annual rate of 2.0% of Terra BDC’s average gross assets. The base management fee was payable quarterly in arrears and calculated based on the average value of Terra BDC’s gross assets at the end of the two most recently completed calendar quarters.

Incentive Fee, Description

The incentive fee consists of two parts. The first part, which was referred to as the subordinated incentive fee on income, was calculated and payable quarterly in arrears based upon Terra BDC’s “pre-incentive fee net investment income” for the immediately preceding quarter. The subordinated incentive fee on income was subject to a quarterly hurdle rate, expressed as a rate of return on adjusted capital at the beginning of the most recently completed calendar quarter, of 2.0% (8.0% annualized), subject to a “catch-up” feature. For this purpose, “pre-incentive fee net investment income” meant interest income, dividend income and any other income (including any other fees, other than fees for providing managerial assistance, such as commitment, origination, structuring, diligence and consulting fees or other fees that Terra BDC received from portfolio companies) accrued during the calendar quarter, minus Terra BDC’s operating expenses for the quarter (including the base management fee, expenses reimbursed to Terra Income Advisors under the Investment Advisory Agreement and any interest expense and dividends paid on any issued and outstanding preferred stock, but excluding the incentive fee). Pre-incentive fee net investment income includes, in the case of investments with a deferred interest feature (such as original issue discount, debt instruments with PIK interest and zero-coupon securities), accrued income that the Company has not yet received in cash. Pre-incentive fee net investment income did not include any realized capital gains, realized capital losses or unrealized capital appreciation or depreciation. The calculation of the subordinated incentive fee on income for each quarter was as follows:•No incentive fee was payable to Terra Income Advisors in any calendar quarter in which Terra BDC’s pre-incentive fee net investment income does not exceed the hurdle rate of 2.0% (8.0% annualized);•100% of Terra BDC’s pre-incentive fee net investment income, if any, that exceeded the hurdle rate but was less than or equal to 2.5% in any calendar quarter (10.0% annualized) was payable to Terra Income Advisors, all or any portion of which may be waived or deferred in Terra Income Advisors’s discretion. This portion of the pre-incentive fee net investment income (which exceeds the hurdle rate but is less than or equal to 2.5%) was referred to as the “catch-up.” The catch-up provision was intended to provide Terra Income Advisors with an incentive fee of 20.0% on all of Terra BDC’s pre-incentive fee net investment income when Terra BDC’s pre-incentive fee net investment income reaches 2.5% in any calendar quarter; and•20.0% of the amount of Terra BDC’s pre-incentive fee net investment income, if any, that exceeded 2.5% in any calendar quarter (10.0% annualized) was payable to Terra Income Advisors once the hurdle rate was reached and the catch-up was achieved. The second part of the incentive fee, which was referred to as the incentive fee on capital gains, was an incentive fee on capital gains earned on liquidated investments from the portfolio and was determined and payable in arrears as of the end of each calendar year (or upon termination of the Investment Advisory Agreement). This fee equaled 20.0% of Terra BDC’s incentive fee on capital gains, which equaled the realized capital gains on a cumulative basis from inception, calculated as of the end of the applicable period, computed net of all realized capital losses and unrealized capital depreciation on a cumulative basis, less the aggregate amount of any previously paid capital gains incentive fees. On a quarterly basis, Terra BDC accrued (but did not pay) for the unrealized capital gains incentive fee by calculating such fee as if it were due and payable as of the end of such period.

Servicing Fee Percent

0.75%

1.125%