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- Definition

Incentive Fee Expense, Capital-Gain-Based, Reversal

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- Definition

Related Party Transaction, Number Of Components Related to Incentive Fee

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- Definition

Share Repurchase Program, Percentage of Outstanding Stock Maximum

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- Definition

Amount, after reimbursement and fee waiver, of expense for generation of investment income classified as operating.

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- Definition

Number of shares of investment owned.

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- Definition

Base rate for management and service fees under arrangement to manage operations, including, but not limited to, investment.

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- Definition

Rate based on performance for management and service fees under arrangement to manage operations, including, but not limited to, investment.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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RELATED PARTY TRANSACTIONS - Narrative (Details) $ in Thousands			3 Months Ended			6 Months Ended
	Jan. 29, 2025	Oct. 30, 2020 component	Jun. 30, 2026 USD ($) shares	Mar. 31, 2026 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2026 USD ($) shares	Jun. 30, 2025 USD ($)	Jan. 20, 2025
Related Party Transaction [Line Items]
Total expenses, net of expense waivers			$ 22,326		$ 18,337	$ 39,172	$ 34,776
Incentive fee on capital gains			$ (2,949)		0	$ (2,311)	0
Share repurchase program, percentage of outstanding stock maximum								3.00%
Related Party \| Main Street
Related Party Transaction [Line Items]
Units (in shares) \| shares			2,025,220			2,025,220
MSC Income \| Advisory Agreement \| Related Party
Related Party Transaction [Line Items]
Base fee rate (as a percent)	1.25%	1.75%				1.50%
Number of components related to incentive fee \| component		2
Advisory agreement, average total assets threshold (as a percent)	7.50%
MSC Income \| Advisory Agreement, Incentive Rate, Pre-Incentive Fee Net Investment Income \| Related Party
Related Party Transaction [Line Items]
Incentive fee rate (as a percent)	17.50%	20.00%
MSC Income \| Advisory Agreement - Incentive Rate, Quarterly Hurdle Rate \| Related Party
Related Party Transaction [Line Items]
Base fee rate (as a percent)	20.00%
Incentive fee rate (as a percent)	1.50%	1.875%
Advisory agreement, average total assets threshold (as a percent)	1.00%
MSC Income \| Advisory Agreement - Incentive Rate, Annualized Hurdle Rate \| Related Party
Related Party Transaction [Line Items]
Incentive fee rate (as a percent)	6.00%	7.50%
MSC Income \| Advisory Agreement, Incentive Rate, Pre-Incentive Fee Net Investment Income Below Catch-Up Threshold \| Related Party
Related Party Transaction [Line Items]
Incentive fee rate (as a percent)	50.00%	100.00%
MSC Income \| Advisory Agreement - Incentive Rate, Quarterly Catch-Up Threshold \| Related Party
Related Party Transaction [Line Items]
Incentive fee rate (as a percent)	2.30769%	2.34375%
MSC Income \| Advisory Agreement - Incentive Rate, Annualized Catch-Up Threshold \| Related Party
Related Party Transaction [Line Items]
Incentive fee rate (as a percent)	9.23077%	9.375%
MSC Income \| Advisory Agreement - Incentive Rate, Pre-Incentive Fee Net Investment Income Exceeds Catch-Up Threshold \| Related Party
Related Party Transaction [Line Items]
Incentive fee rate (as a percent)	17.50%	20.00%
MSC Income \| Advisory Agreement - Subordinated Incentive Fees \| Related Party
Related Party Transaction [Line Items]
Total expenses, net of expense waivers			$ 5,100	$ 2,100
MSC Income \| Advisory Agreement - Incentive Fees, Capital Gains Fees \| Related Party
Related Party Transaction [Line Items]
Incentive fee on capital gains			$ 2,949		$ 0	$ 2,311	$ 0