SUBSEQUENT EVENTS	6 Months Ended
Jun. 30, 2026
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS The Company’s management has evaluated subsequent events through the date of issuance of the consolidated financial statements, and identified the following to report: In August 2026, Main Street declared a supplemental dividend of $0.30 per share payable in September 2026. This supplemental dividend is in addition to the previously announced regular monthly dividends that Main Street declared of $0.265 per share for each month of July, August and September 2026, or total regular monthly dividends of $0.795 per share for the third quarter of 2026, resulting in total dividends declared for the third quarter of 2026 of $1.095 per share. In August 2026, Main Street also declared regular monthly dividends of $0.265 per share for each month of October, November and December of 2026. These regular monthly dividends equal a total of $0.795 per share for the fourth quarter of 2026, representing a 3.9% increase from the regular monthly dividends paid in the fourth quarter of 2025. Including the regular monthly and supplemental dividends declared through the fourth quarter of 2026, Main Street will have paid $51.205 per share in cumulative dividends since its October 2007 initial public offering. In August 2026, Main Street’s Board of Directors authorized the Company to enter into a share purchase plan to purchase up to $20.0 million of shares of MSC Income’s common stock in the open market for a period beginning in September 2026 and ending in February 2027 at times when the market price per share of MSC Income’s common stock is trading below the most recently reported NAV per share of the common stock by certain pre-determined levels. The purchases of shares of MSC Income common stock pursuant to the share purchase plan are intended to satisfy the conditions of Rule 10b5-1 and Rule 10b-18 under the Exchange Act and will otherwise be subject to applicable law, including Regulation M, which may prohibit purchases under certain circumstances. MSC Income’s board of directors also authorized MSC Income to enter into a share repurchase plan to purchase up to $20.0 million of shares of its common stock, with the terms and conditions substantially similar between Main Street’s share purchase plan for shares of MSC Income common stock and MSC Income’s share repurchase plan, and daily purchases under the two plans, if any, are expected to be split pro rata (or as close thereto as reasonably possible) between Main Street and MSC Income based on the respective plan sizes.

In August 2026, Main Street declared a supplemental dividend of $0.30 per share payable in September 2026. This supplemental dividend is in addition to the previously announced regular monthly dividends that Main Street declared of $0.265 per share for each month of July, August and September 2026, or total regular monthly dividends of $0.795 per share for the third quarter of 2026, resulting in total dividends declared for the third quarter of 2026 of $1.095 per share.

In August 2026, Main Street also declared regular monthly dividends of $0.265 per share for each month of October, November and December of 2026. These regular monthly dividends equal a total of $0.795 per share for the fourth quarter of 2026, representing a 3.9% increase from the regular monthly dividends paid in the fourth quarter of 2025. Including the regular monthly and supplemental dividends declared through the fourth quarter of 2026, Main Street will have paid $51.205 per share in cumulative dividends since its October 2007 initial public offering.

In August 2026, Main Street’s Board of Directors authorized the Company to enter into a share purchase plan to purchase up to $20.0 million of shares of MSC Income’s common stock in the open market for a period beginning in September 2026 and ending in February 2027 at times when the market price per share of MSC Income’s common stock is trading below the most recently reported NAV per share of the common stock by certain pre-determined levels. The purchases of shares of MSC Income common stock pursuant to the share purchase plan are intended to satisfy the conditions of Rule 10b5-1 and Rule 10b-18 under the Exchange Act and will otherwise be subject to applicable law, including Regulation M, which may prohibit purchases under certain circumstances. MSC Income’s board of directors also authorized MSC Income to enter into a share repurchase plan to purchase up to $20.0 million of shares of its common stock, with the terms and conditions substantially similar between Main Street’s share purchase plan for shares of MSC Income common stock and MSC Income’s share repurchase plan, and daily purchases under the two plans, if any, are expected to be split pro rata (or as close thereto as reasonably possible) between Main Street and MSC Income based on the respective plan sizes.