Financial Highlights (Details) - Schedule of financial highlights - USD ($)		12 Months Ended
		Feb. 28, 2023		Feb. 28, 2022		Feb. 28, 2021	Feb. 29, 2020	Feb. 28, 2019
Investment Company, Financial Highlights [Line Items]
Net asset value at beginning of period		$ 29.33		$ 27.25		$ 27.13	$ 23.62	$ 22.96
Adoption of ASC 606								(0.01)
Net investment income	[1]	2.94		1.74		2.07	1.59	2.6
Net realized and unrealized gain and losses on investments	[1]	(0.75)		2.46		(0.74)	4.56	0.03
Realized losses on extinguishment of debt	[2]	(0.13)		(0.21)		(0.01)	(0.17)
Net increase in net assets resulting from operations		2.06		3.99		1.32	5.98	2.63
Distributions declared from net investment income		(2.28)		(1.93)		(1.23)	(2.21)	(2.06)
Total distributions to stockholders		(2.28)		(1.93)		(1.23)	(2.21)	(2.06)
Issuance of common stock above net asset value	[3]							0.15
Repurchases of common stock	[4]	0.17		0.01		0.13
Dilution		(0.1)	[5]		[5]	(0.1)	(0.26)	(0.05)
Net asset value at end of period		$ 29.18		$ 29.33		$ 27.25	$ 27.13	$ 23.62
Net assets at end of period (in Dollars)		$ 346,958,042		$ 355,780,523		$ 304,185,770	$ 304,286,853	$ 180,875,187
Shares outstanding at end of period (in Shares)		11,890,500		12,131,350		11,161,416	11,217,545	7,657,156
Per share market value at end of period		$ 27.55		$ 27.47		$ 23.08	$ 22.91	$ 23.04
Total return based on market value	[6],[7]	10.35%		28.19%		7.63%	9.28%	16.11%
Total return based on net asset value	[7],[8]	9.46%		15.88%		7.31%	26.22%	13.33%
Ratio/Supplemental data:
Ratio of net investment income to average net assets	[9]	10.23%		6.05%		7.77%	6.31%	11.22%
Ratio of loss on extinguishment of debt to average net assets	[7]	0.46%		0.74%		0.04%	0.67%
Ratios of Operating Expenses and Income Taxes to average net assets	[2],[10]	7.71%		6.48%		6.90%	6.10%	8.07%
Ratio of incentive management fees to average net assets	[7]	1.47%		3.58%		1.65%	6.01%	3.00%
Ratio of interest and debt financing expenses to average net assets	[10]	9.73%		6.03%		4.56%	6.23%	8.05%
Ratio of total expenses and income taxes to average net assets	[9]	18.91%	[2]	16.09%	[2]	13.11%	18.34%	19.12%
Portfolio turnover rate	[7],[11]	24.05%		33.59%		25.26%	36.82%	35.26%
Asset coverage ratio per unit (in Dollars)	[12]	$ 1,659		$ 2,092		$ 3,471	$ 6,071	$ 2,345
Average market value per unit
Revolving Credit Facility	[13]
SBA Debentures Payable	[13]
As adjusted [Member]
Investment Company, Financial Highlights [Line Items]
Net asset value at beginning of period, as adjusted (in Dollars)		$ 29.33		$ 27.25		$ 27.13	$ 23.62	$ 22.95
6.75% Notes Payable 2023 [Member]
Average market value per unit
Average market value per unit								$ 25.74
6.25% Notes Payable 2025 [Member]
Average market value per unit
Average market value per unit						24.24	25.75	24.97
7.00% Notes Payable 2025 [Member]
Average market value per unit
Average market value per unit	[13]
7.25% Notes Payable 2025 [Member]
Average market value per unit
Average market value per unit				26.18		25.77
7.75% Notes Payable 2025 [Member]
Average market value per unit
Average market value per unit	[13]
4.375% Notes Payable [Member]
Average market value per unit
Average market value per unit	[13]
4.35% Notes Payable [Member]
Average market value per unit
Average market value per unit	[13]
6.25% Notes Payable 2027 [Member]
Average market value per unit
Average market value per unit	[13]
6.00% Notes Payable 2027 [Member]
Average market value per unit
Average market value per unit		23.97
8.00% Notes Payable 2027 [Member]
Average market value per unit
Average market value per unit		25.08
8.125% Notes Payable 2027 [Member]
Average market value per unit
Average market value per unit		$ 25.1

[1] Per share amounts are calculated using the weighted average shares outstanding during the period.

[2] Certain prior period amounts have been reclassified to conform to current period presentation.

[3] The continuous issuance of common stock may cause an incremental increase in NAV per share due to the sale of shares at the then prevailing public offering price and the receipt of net proceeds per share by the Company in excess of NAV per share on each subscription closing date. The per share data was derived by computing (i) the sum of (A) the number of shares issued in connection with subscriptions and/or distribution reinvestment on each share transaction date multiplied by (B) the differences between the net proceeds per share and the NAV per share on each share transaction date, divided by (ii) the total shares outstanding during the period.

[4] Represents the anti-dilutive impact on the NAV per share of the Company due to the repurchase of common shares.

[5] Represents the dilutive effect of issuing common stock below NAV per share during the period in connection with the satisfaction of the Company’s annual RIC distribution requirement and may include the impact of the different share amounts used for different items (weighted average basic common shares outstanding for the corresponding year and actual common shares outstanding at the end of the year) in the per common share data calculation and rounding impacts. See Note 13, Dividend.

[6] Total investment return is calculated assuming a purchase of common shares at the current NAV on the first day and a sale at the current NAV on the last day of the periods reported. Dividends and distributions, if any, are assumed for purposes of this calculation to be reinvested at prices obtained under the DRIP. Total investment return does not reflect brokerage commissions.

[7] Total investment return is calculated assuming a purchase of common shares at the current market value on the first day and a sale at the current market value on the last day of the periods reported. Dividends and distributions, if any, are assumed for purposes of this calculation to be reinvested at prices obtained under the DRIP. Total investment return does not reflect brokerage commissions.

[8] Portfolio turnover rate is calculated using the lesser of year-to-date sales or year-to-date purchases over the average of the invested assets at fair value.

[9] Asset coverage ratio per unit is the ratio of the carrying value of our total consolidated assets, less all liabilities and indebtedness not represented by senior securities, to the aggregate amount of senior securities representing indebtedness. Asset coverage ratio per unit is expressed in terms of dollar amounts per $1,000 of indebtedness. Asset coverage ratio per unit does not include unfunded commitments. The inclusion of unfunded commitments in the calculation of the asset coverage ratio per unit would not cause us to be below the required amount of regulatory coverage.

[10] The Revolving Credit Facility, SBA Debentures, 7.00% Notes Payable 2025, 4.375% Notes Payable 2026, 4.35% Notes Payable 2026, 7.75% Notes Payable 2025 and 6.25% Notes Payable 2027 are not registered for public trading.

[11] On December 21, 2019 and February 7, 2020, the Company redeemed $50.0 million and $24.5 million, respectively, in aggregate principal amount of the $74.5 million in aggregate principal amount of issued and outstanding 2023 Notes and are no longer listed on the NYSE.

[12] On August 31, 2021, the Company redeemed $60.0 million in aggregate principal amount of the issued and outstanding 6.25% 2025 Notes and, as a result of the full redemption, the 6.25% 2025 Notes are no longer listed on the NYSE.

[13] On July 14, 2022, the Company redeemed $43.1 million in aggregate principal amount of the $43.1 million in aggregate principal amount of issued and outstanding 7.25% 2025 Notes and are no longer listed on the NYSE.