v3.26.1
Shareholders’ Equity - Schedule of Distributions (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 9 Months Ended
Jun. 30, 2026
Mar. 31, 2026
Dec. 31, 2025
Jun. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
Jun. 30, 2026
Jun. 30, 2025
Common class A and B1                
Class of Stock [Line Items]                
Dividends paid (in dollars per share) $ 0.45 $ 0.45 $ 0.45 $ 0.45 $ 0.45 $ 0.45 $ 1.35 $ 1.35
Value of dividends $ 7,692 $ 7,676 $ 7,678 $ 7,595 $ 7,580 $ 7,581 $ 23,046 $ 22,756
Membership Units | RMR LLC                
Class of Stock [Line Items]                
Dividends paid (in dollars per share) $ 0.32 $ 0.32 $ 0.32 $ 0.32 $ 0.32 $ 0.32 $ 0.96 $ 0.96
Value of dividends $ 10,270 $ 10,259 $ 10,260 $ 10,201 $ 10,190 $ 10,191 $ 30,789 $ 30,582
Membership Units | RMR LLC | RMR, Inc                
Class of Stock [Line Items]                
Value of dividends 5,470 5,459 5,460 5,401 5,390 5,391 16,389 16,182
Membership Units | RMR LLC | Abp Trust                
Class of Stock [Line Items]                
Value of dividends $ 4,800 $ 4,800 $ 4,800 $ 4,800 $ 4,800 $ 4,800 $ 14,400 $ 14,400