The RMR Group Inc. (RMR) 10-Q 9 Aug 23 2023 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Jun. 30, 2023	Aug. 08, 2023
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2023
Document Transition Report	false
Entity File Number	001-37616
Entity Registrant Name	RMR GROUP INC.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	47-4122583
Entity Address, Address Line One	Two Newton Place
Entity Address, Address Line Two	255 Washington Street
Entity Address, Address Line Three	Suite 300
Entity Address, City or Town	Newton
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02458-1634
City Area Code	617
Local Phone Number	796-8230
Title of 12(b) Security	Class A common stock, $0.001 par value per share
Trading Symbol	RMR
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0001644378
Amendment Flag	false
Current Fiscal Year End Date	--09-30
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Class A Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		15,612,179
Class B-1 Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		1,000,000
Class B-2 Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		15,000,000

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Current assets:
Cash and cash equivalents	$ 295,423	$ 189,088
Prepaid and other current assets	6,486	5,372
Total current assets	404,010	303,281
Property and equipment, net	5,501	2,495
Equity method investments accounted for under the fair value option	17,525	49,114
Goodwill and intangible assets, net of amortization	2,034	2,057
Operating lease right of use assets	29,272	28,894
Deferred tax asset	18,578	17,112
Other assets, net of amortization	117,833	124,895
Total assets	601,385	542,405
Current liabilities:
Reimbursable accounts payable and accrued expenses	74,263	80,221
Accounts payable and accrued expenses	40,316	16,745
Operating lease liabilities	5,056	4,693
Employer compensation liability	1,039	7,516
Total current liabilities	120,674	109,175
Operating lease liabilities, net of current portion	25,406	25,626
Amounts due pursuant to tax receivable agreement, net of current portion	23,308	23,308
Employer compensation liability, net of current portion	6,632	14,557
Total liabilities	176,020	172,666
Commitments and contingencies
Equity:
Additional paid in capital	115,479	113,136
Retained earnings	405,400	355,949
Cumulative common distributions	(282,427)	(262,496)
Total shareholders’ equity	238,484	206,621
Noncontrolling interest	186,881	163,118
Total equity	425,365	369,739
Total liabilities and equity	601,385	542,405
Related Party
Current assets:
Due from related parties	102,101	108,821
Due from related parties, net of current portion	6,632	14,557
Class A Common Stock
Equity:
Common stock	16	16
Class B-1 Common Stock
Equity:
Common stock	1	1
Class B-2 Common Stock
Equity:
Common stock	$ 15	$ 15

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2023	Sep. 30, 2022
Class A Common Stock
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	31,950,000	31,600,000
Common stock, shares issued (in shares)	15,614,152	15,606,115
Common stock shares outstanding (in shares)	15,614,152	15,606,115
Class B-1 Common Stock
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	1,000,000	1,000,000
Common stock, shares issued (in shares)	1,000,000	1,000,000
Common stock shares outstanding (in shares)	1,000,000	1,000,000
Class B-2 Common Stock
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	15,000,000	15,000,000
Common stock, shares issued (in shares)	15,000,000	15,000,000
Common stock shares outstanding (in shares)	15,000,000	15,000,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenues:
Total revenues	$ 280,225	$ 211,088	$ 739,384	$ 590,310
Expenses:
Compensation and benefits	34,239	32,170	102,039	95,671
Equity based compensation	2,100	512	8,719	4,719
Separation costs	1,064	400	2,002	617
Total compensation and benefits expense	37,403	33,082	112,760	101,007
General and administrative	9,575	8,323	28,198	24,464
Other reimbursable expenses	170,881	144,012	497,465	397,063
Transaction and acquisition related costs	1,196	0	1,196	0
Depreciation and amortization	281	253	821	731
Total expenses	219,336	185,670	640,440	523,265
Operating income	60,889	25,418	98,944	67,045
Interest income	2,833	279	6,837	402
Gain (loss) on equity method investments accounted for under the fair value option	663	(5,489)	23,513	(8,853)
Income before income tax expense	64,385	20,208	129,294	58,594
Income tax expense	(9,214)	(2,943)	(18,581)	(8,448)
Net income	55,171	17,265	110,713	50,146
Net income attributable to noncontrolling interest	(30,530)	(9,695)	(61,262)	(28,142)
Net income attributable to The RMR Group Inc.	$ 24,641	$ 7,570	$ 49,451	$ 22,004
Weighted average common shares outstanding - basic (in shares)	16,435	16,343	16,416	16,332
Weighted average common shares outstanding - diluted (in shares)	16,435	31,353	31,431	31,342
Net income attributable to The RMR Group Inc. per common share - basic (in dollars per share)	$ 1.48	$ 0.46	$ 2.98	$ 1.33
Net income attributable to The RMR Group Inc. per common share - diluted (in dollars per share)	$ 1.48	$ 0.46	$ 2.97	$ 1.33
Total management and advisory services revenues
Revenues:
Total revenues	$ 92,487	$ 52,956	$ 190,335	$ 148,259
Management services
Revenues:
Total revenues	45,872	51,819	141,490	144,867
Termination and incentive business management fees
Revenues:
Total revenues	45,474	0	45,474	0
Advisory services
Revenues:
Total revenues	1,141	1,137	3,371	3,392
Total reimbursable costs
Revenues:
Total revenues	187,738	158,132	549,049	442,051
Reimbursable compensation and benefits
Revenues:
Total revenues	15,235	14,189	44,441	42,092
Reimbursable equity based compensation
Revenues:
Total revenues	1,622	(69)	7,143	2,896
Other reimbursable expenses
Revenues:
Total revenues	$ 170,881	$ 144,012	$ 497,465	$ 397,063

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Total Shareholders' Equity	Common Stock Class A Common Stock	Common Stock Class B-1 Common Stock	Common Stock Class B-2 Common Stock	Additional Paid In Capital	Retained Earnings	Cumulative Common Distributions	Noncontrolling Interest
Beginning balance at Sep. 30, 2021	$ 347,715	$ 195,120	$ 15	$ 1	$ 15	$ 109,910	$ 321,945	$ (236,766)	$ 152,595
Increase (Decrease) in Shareholders' Equity
Share awards, net	613	613				613
Net income	18,292	8,042					8,042		10,250
Tax distributions to member	(1,979)								(1,979)
Common share distributions	(10,764)	(6,264)						(6,264)	(4,500)
Ending balance at Dec. 31, 2021	353,877	197,511	15	1	15	110,523	329,987	(243,030)	156,366
Beginning balance at Sep. 30, 2021	347,715	195,120	15	1	15	109,910	321,945	(236,766)	152,595
Increase (Decrease) in Shareholders' Equity
Net income	50,146
Ending balance at Jun. 30, 2022	357,008	200,481	16	1	15	112,396	343,949	(255,896)	156,527
Beginning balance at Dec. 31, 2021	353,877	197,511	15	1	15	110,523	329,987	(243,030)	156,366
Increase (Decrease) in Shareholders' Equity
Share awards, net	1,145	1,145	1			1,144
Net income	14,589	6,392					6,392		8,197
Tax distributions to member	(4,277)								(4,277)
Common share distributions	(10,765)	(6,265)						(6,265)	(4,500)
Ending balance at Mar. 31, 2022	354,569	198,783	16	1	15	111,667	336,379	(249,295)	155,786
Increase (Decrease) in Shareholders' Equity
Share awards, net	729	729				729
Net income	17,265	7,570					7,570		9,695
Tax distributions to member	(4,154)								(4,154)
Common share distributions	(11,401)	(6,601)						(6,601)	(4,800)
Ending balance at Jun. 30, 2022	357,008	200,481	16	1	15	112,396	343,949	(255,896)	156,527
Beginning balance at Sep. 30, 2022	369,739	206,621	16	1	15	113,136	355,949	(262,496)	163,118
Increase (Decrease) in Shareholders' Equity
Share awards, net	594	594				594
Net income	14,240	6,337					6,337		7,903
Tax distributions to member	(3,839)								(3,839)
Common share distributions	(11,442)	(6,642)						(6,642)	(4,800)
Ending balance at Dec. 31, 2022	369,292	206,910	16	1	15	113,730	362,286	(269,138)	162,382
Beginning balance at Sep. 30, 2022	369,739	206,621	16	1	15	113,136	355,949	(262,496)	163,118
Increase (Decrease) in Shareholders' Equity
Net income	110,713
Ending balance at Jun. 30, 2023	425,365	238,484	16	1	15	115,479	405,400	(282,427)	186,881
Beginning balance at Dec. 31, 2022	369,292	206,910	16	1	15	113,730	362,286	(269,138)	162,382
Increase (Decrease) in Shareholders' Equity
Share awards, net	1,015	1,015				1,015
Net income	41,302	18,473					18,473		22,829
Tax distributions to member	(4,545)								(4,545)
Common share distributions	(11,441)	(6,641)						(6,641)	(4,800)
Ending balance at Mar. 31, 2023	395,623	219,757	16	1	15	114,745	380,759	(275,779)	175,866
Increase (Decrease) in Shareholders' Equity
Share awards, net	734	734				734
Net income	55,171	24,641					24,641		30,530
Tax distributions to member	(14,715)								(14,715)
Common share distributions	(11,448)	(6,648)						(6,648)	(4,800)
Ending balance at Jun. 30, 2023	$ 425,365	$ 238,484	$ 16	$ 1	$ 15	$ 115,479	$ 405,400	$ (282,427)	$ 186,881

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash Flows from Operating Activities:
Net income	$ 110,713	$ 50,146
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	821	731
Straight line office rent	(235)	(247)
Amortization expense related to other assets	7,062	7,062
Deferred income taxes	(1,466)	(132)
Operating expenses paid in The RMR Group Inc. common shares	2,522	2,518
Distributions from equity method investments	1,623	415
(Gain) loss on equity method investments accounted for under the fair value option	(23,513)	8,853
Changes in assets and liabilities:
Due from related parties	243	(8,550)
Prepaid and other current assets	(1,114)	18
Reimbursable accounts payable and accrued expenses	(5,958)	12,205
Accounts payable and accrued expenses	22,994	16,837
Net cash from operating activities	113,692	89,856
Cash Flows from Investing Activities:
Purchase of property and equipment	(3,227)	(915)
Equity method investment in Seven Hills Realty Trust	0	(9,469)
Proceeds from sale of TravelCenters of America Inc. common shares	53,479	0
Net cash provided by (used in) investing activities	50,252	(10,384)
Cash Flows from Financing Activities:
Distributions to noncontrolling interest	(37,499)	(24,210)
Distributions to common shareholders	(19,931)	(19,130)
Repurchase of common shares	(179)	(31)
Net cash used in financing activities	(57,609)	(43,371)
Increase in cash and cash equivalents	106,335	36,101
Cash and cash equivalents at beginning of period	189,088	159,835
Cash and cash equivalents at end of period	295,423	195,936
Supplemental Cash Flow Information and Non-Cash Activities:
Income taxes paid	16,978	7,392
Recognition of right of use assets and related lease liabilities	$ 4,119	$ 783

Basis of Presentation

Basis of Presentation	9 Months Ended
	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The RMR Group Inc., or RMR Inc., is a holding company and substantially all of its business is conducted by its majority owned subsidiary, The RMR Group LLC, or RMR LLC. RMR Inc. is a Maryland corporation and RMR LLC is a Maryland limited liability company. RMR Inc. serves as the sole managing member of RMR LLC and, in that capacity, operates and controls the business and affairs of RMR LLC. In these financial statements, unless otherwise indicated, “we”, “us” and “our” refer to RMR Inc. and its direct and indirect subsidiaries, including RMR LLC. As of June 30, 2023, RMR Inc. owned 15,614,152 class A membership units of RMR LLC, or Class A Units, and 1,000,000 class B membership units of RMR LLC, or Class B Units. The aggregate RMR LLC membership units RMR Inc. owns represented 52.6% of the economic interest of RMR LLC as of June 30, 2023. We refer to economic interest as the right of a holder of a Class A Unit or Class B Unit to share in distributions made by RMR LLC and, upon liquidation, dissolution or winding up of RMR LLC, to share in the assets of RMR LLC after payments to creditors. A wholly owned subsidiary of ABP Trust, a Maryland statutory trust, owns 15,000,000 redeemable Class A Units, representing 47.4% of the economic interest of RMR LLC as of June 30, 2023, which is presented as a noncontrolling interest within the condensed consolidated financial statements. Adam D. Portnoy, the Chair of our Board, one of our Managing Directors and our President and Chief Executive Officer, is the sole trustee of ABP Trust, and owns all of ABP Trust’s voting securities. RMR LLC was founded in 1986 to manage public investments in real estate and, as of June 30, 2023, managed a diverse portfolio of real estate and real estate related businesses. RMR LLC provides management services to four publicly traded equity real estate investment trusts, or REITs: Diversified Healthcare Trust, or DHC, which owns medical office and life science properties, senior living communities and wellness centers; Industrial Logistics Properties Trust, or ILPT, which owns and leases industrial and logistics properties; Office Properties Income Trust, or OPI, which owns office properties primarily leased to single tenants and those with high quality credit characteristics, including the government; and Service Properties Trust, or SVC, which owns a diverse portfolio of hotels and net lease service and necessity-based retail properties. DHC, ILPT, OPI and SVC are collectively referred to as the Managed Equity REITs. On April 11, 2023, OPI and DHC entered into an agreement to merge, pursuant to which DHC will be merged with and into OPI, with OPI continuing as the surviving entity in the merger. RMR LLC will continue to manage the surviving entity following the merger. For additional information, see Note 6, Related Person Transactions. RMR LLC’s wholly owned subsidiary, Tremont Realty Capital LLC, or Tremont, an investment adviser registered with the Securities and Exchange Commission, or SEC, provides advisory services for Seven Hills Realty Trust, or SEVN. SEVN is a publicly traded mortgage REIT that focuses on originating and investing in first mortgage loans secured by middle market and transitional commercial real estate. Tremont has in the past and may in the future manage additional accounts that invest in commercial real estate debt. Tremont may also act as a transaction broker for non-investment advisory clients for negotiated fees, which we refer to as the Tremont business. RMR LLC also provided management services to TravelCenters of America Inc., or TA, until it was acquired by BP Products North America Inc., or BP, on May 15, 2023. TA is a real estate operating company that operates and franchises travel centers primarily along the U.S. interstate highway system, many of which are owned by SVC, and standalone truck service facilities. The Managed Equity REITs, SEVN, and until May 15, 2023, TA, are collectively referred to as the Perpetual Capital clients. In addition, RMR LLC provides management services to private capital vehicles, including ABP Trust, AlerisLife Inc., or AlerisLife, Sonesta International Hotels Corporation, or Sonesta, and other private entities that own commercial real estate, of which certain of our Managed Equity REITs own minority equity interests. These clients are collectively referred to as the Private Capital clients. AlerisLife is an operator of senior living communities, many of which are owned by DHC, and as discussed in Note 6, Related Person Transactions , was a publicly traded company until March 20, 2023 when it was acquired by a subsidiary of ABP Trust. As a result of this transaction, amounts relating to AlerisLife are characterized as Private Capital for all periods presented. Sonesta is a privately owned franchisor and operator of hotels, resorts and cruise ships in the United States, Latin America, the Caribbean and the Middle East, and many of the U.S. hotels that Sonesta operates are owned by SVC. The accompanying condensed consolidated financial statements are unaudited. Certain information and disclosures required by U.S. Generally Accepted Accounting Principles, or GAAP, for complete financial statements have been condensed or omitted. We believe the disclosures made are adequate to make the information presented not misleading. However, the accompanying condensed consolidated financial statements should be read in conjunction with the financial statements and notes contained in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022, or our 2022 Annual Report. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair statement of results for the interim period have been included. All intercompany transactions and balances with or among our consolidated subsidiaries have been eliminated. Our operating results for interim periods are not necessarily indicative of the results that may be expected for the full year. We report our results in a single reportable segment, which reflects how our chief operating decision maker allocates resources and evaluates our financial results. Preparation of these financial statements in conformity with GAAP requires our management to make certain estimates and assumptions that may affect the amounts reported in these condensed consolidated financial statements and related notes. The actual results could differ from these estimates.

Revenue Recognition

Revenue Recognition	9 Months Ended
	Jun. 30, 2023
Revenue Recognition [Abstract]
Revenue Recognition	Revenue Recognition Revenues from services that we provide are recognized as earned over time as the services provided represent performance obligations that are satisfied over time. Management Agreements with the Managed Equity REITs We are party to a business management and a property management agreement with each Managed Equity REIT. The following is a summary of the fees we earn pursuant to our business management agreements with the Managed Equity REITs. For a summary of the fees we earn pursuant to our property management agreements with the Managed Equity REITs, please see Property Management Agreements , below. Base Business Management Fees — We earn annual base business management fees from the Managed Equity REITs by providing continuous services pursuant to business management agreements equal to the lesser of: • the sum of (a) 0.5% of the historical cost of transferred real estate assets, if any, as defined in the applicable business management agreement, plus (b) 0.7% of the average invested capital (exclusive of the transferred real estate assets), as defined in the applicable business management agreement, up to $250,000, plus (c) 0.5% of the average invested capital exceeding $250,000; and • the sum of (a) 0.7% of the average market capitalization, as defined in the applicable business management agreement, up to $250,000, plus (b) 0.5% of the average market capitalization exceeding $250,000. The foregoing base business management fees are paid in cash monthly in arrears. We earned aggregate base business management fees from the Managed Equity REITs of $21,037 and $25,446 for the three months ended June 30, 2023 and 2022, respectively, and $63,894 and $73,085 for the nine months ended June 30, 2023 and 2022, respectively. Incentive Business Management Fees — We also may earn annual incentive business management fees from the Managed Equity REITs under the business management agreements. The incentive business management fees, which are payable in cash, are contingent performance based fees recognized only when earned at the end of each respective measurement period. Incentive business management fees are excluded from the transaction price until it becomes probable that there will not be a significant reversal of cumulative revenue recognized. The incentive business management fees are calculated for each Managed Equity REIT as 12.0% of the product of (a) the equity market capitalization of the Managed Equity REIT, as defined in the applicable business management agreement, on the last trading day of the year immediately prior to the relevant measurement period and (b) the amount, expressed as a percentage, by which the Managed Equity REIT’s total return per share, as defined in the applicable business management agreement, exceeded the applicable benchmark total return per share, as defined in the applicable business management agreement, of a specified REIT index identified in the applicable business management agreement for the measurement period, as adjusted for net share issuances during the period and subject to caps on the values of the incentive fees. The measurement period for the annual incentive business management fees is defined as the three year period ending on December 31 of the year for which such fee is being calculated. We did not earn incentive business management fees from the Managed Equity REITs for calendar years 2022 or 2021. Other Management Agreements We earn management fees by providing continuous services pursuant to the management agreements with AlerisLife, Sonesta and until May 15, 2023, TA, equal to 0.6% of: (i) in the case of AlerisLife, AlerisLife’s revenues from all sources reportable under GAAP, less any revenues reportable by AlerisLife with respect to properties for which it provides management services, plus the gross revenues at those properties determined in accordance with GAAP; (ii) in the case of Sonesta, Sonesta’s revenues from all sources reportable under GAAP, less any revenues reportable by Sonesta with respect to hotels for which it provides management services, plus the gross revenues at those hotels determined in accordance with GAAP; and (iii) in the case of TA, the sum of TA’s gross fuel margin, as defined in the applicable agreement, plus TA’s total nonfuel revenues. These management fees are estimated and payable in cash monthly in advance. We also earn management fees from certain Private Capital clients based on a percentage of average invested capital, as defined in the applicable management agreements. These management fees are payable in cash monthly in arrears. We earned aggregate base business management fees from TA and the Private Capital clients of $9,134 and $11,107 for the three months ended June 30, 2023 and 2022, respectively, and $29,874 and $28,296 for the nine months ended June 30, 2023 and 2022, respectively. In addition, in connection with BP’s acquisition of TA on May 15, 2023, TA terminated its business management agreement with us and paid us the applicable termination fee of $45,282. Property Management Agreements We earn property management fees by providing continuous services pursuant to property management agreements with the Managed Equity REITs and certain Private Capital clients. We generally earn fees under these agreements equal to 3.0% of gross collected rents. Also, under the terms of the property management agreements, we receive additional fees for construction supervision services up to 5.0% of the cost of such construction. For the three months ended June 30, 2023 and 2022, we earned aggregate property management fees of $15,649 and $15,220, respectively, including construction supervision fees of $4,418 and $4,596, respectively. For the nine months ended June 30, 2023 and 2022, we earned aggregate property management fees of $47,670 and $43,387, respectively, including construction supervision fees of $14,120 and $11,623, respectively. Management Agreements with Advisory Clients Tremont is primarily compensated pursuant to its management agreement with SEVN at an annual rate of 1.5% of equity, as defined in the applicable agreement. We earned advisory services revenue of $1,141 and $1,137 for the three months ended June 30, 2023 and 2022, respectively, and $3,371 and $3,392 for the nine months ended June 30, 2023 and 2022, respectively. Tremont may also earn an incentive fee under its management agreement with SEVN equal to the difference between: (a) the product of (i) 20% and (ii) the difference between (A) core earnings, as defined in the agreement, for the most recent 12 month period (or such lesser number of completed calendar quarters, if applicable), including the calendar quarter (or part thereof) for which the calculation of the incentive fee is being made, and (B) the product of (1) equity in the most recent 12 month period (or such lesser number of completed calendar quarters, if applicable), including the calendar quarter (or part thereof) for which the calculation of the incentive fee is being made, and (2) 7% per year and (b) the sum of any incentive fees paid to Tremont with respect to the first three calendar quarters of the most recent 12 month period (or such lesser number of completed calendar quarters preceding the applicable period, if applicable). No incentive fee shall be payable with respect to any calendar quarter unless core earnings for the 12 most recently completed calendar quarters in the aggregate is greater than zero. The incentive fee may not be less than zero. Tremont earned incentive fees from SEVN of $192 for the three and nine months ended June 30, 2023. Tremont did not earn incentive fees from SEVN for the three or nine months ended June 30, 2022. The Tremont business earns between 0.5% and 1.0% of the aggregate principal amounts of any loans it brokers. The Tremont business earned fees for such brokerage services of $52 and $46 for the three months ended June 30, 2023 and 2022, respectively, and $52 and $99 for the nine months ended June 30, 2023 and 2022, respectively, which amounts are included in management services revenue in our condensed consolidated statements of income. Reimbursable Costs Reimbursable Compensation and Benefits — Reimbursable compensation and benefits include reimbursements, at cost, that arise primarily from services our employees provide pursuant to our property management agreements at the properties of our clients. A significant portion of these compensation and benefits are charged or passed through to and paid by tenants of our clients. We recognize the revenue for reimbursements when we incur the related reimbursable compensation and benefits expense on behalf of our clients. Reimbursable Equity Based Compensation — Reimbursable equity based compensation includes awards of common shares by our clients directly to certain of our officers and employees in connection with the provision of management services to those clients. The revenue in respect of each award is based on the fair value as of the award date for those shares that have vested, with subsequent changes in the fair value of the unvested awards being recognized in our condensed consolidated statements of income over the requisite service periods. We record an equal, offsetting amount as equity based compensation expense for the value of these awards. Other Reimbursable Expenses —

Equity Method Investments

Equity Method Investments	9 Months Ended
	Jun. 30, 2023
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments Seven Hills Realty Trust As of June 30, 2023, Tremont owned 1,708,058, or approximately 11.6%, of SEVN’s outstanding common shares. We account for our investment in SEVN using the equity method of accounting because we are deemed to exert significant influence, but not control, over SEVN’s most significant activities. We elected the fair value option to account for our equity method investment in SEVN and determine fair value using the closing price of SEVN’s common shares as of the end of the period, which is a Level 1 fair value input. The aggregate market value of our investment in SEVN at June 30, 2023 and September 30, 2022, based on quoted market prices, was $17,525 and $15,577, respectively. The unrealized gain (loss) in our condensed consolidated statements of income related to our investment in SEVN was $974 and $(209) for the three months ended June 30, 2023 and 2022, respectively, and $3,571 and $675 for the nine months ended June 30, 2023 and 2022, respectively. We received distributions from SEVN of $598 and $207 for the three months ended June 30, 2023 and 2022, respectively, and $1,623 and $415 for the nine months ended June 30, 2023 and 2022, respectively. TravelCenters of America Inc. We previously owned 621,853, or approximately 4.1%, of TA’s outstanding common shares, that had a cost of $13,701 and were accounted for using the equity method of accounting under the fair value option. As discussed in Note 6, Related Person Transactions , BP acquired TA on May 15, 2023 for $86.00 per share in cash. In connection with that acquisition, we received $53,479 for the TA common shares we owned and realized a gain of $39,778. We previously accounted for our investment in TA using the equity method of accounting because we were deemed to exert significant influence, but not control, over TA’s most significant activities. Under the fair value option, we determined fair value using the closing price of TA’s common shares as of the end of the period, which was a Level 1 fair value input, and recorded changes in fair value in earnings in our condensed consolidated statements of income. Net gains and losses recorded in our condensed consolidated statements of income related to our investment in TA was $(311) and $5,280 for the three months ended June 30, 2023 and 2022, respectively, and $19,942 and $(9,528) for the nine months ended June 30, 2023 and 2022, respectively.

Income Taxes

Income Taxes	9 Months Ended
	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We are the sole managing member of RMR LLC. We are a corporation subject to U.S. federal and state income tax with respect to our allocable share of any taxable income of RMR LLC and its tax consolidated subsidiaries. RMR LLC is treated as a partnership for U.S. federal and most applicable state and local income tax purposes. As a partnership, RMR LLC is generally not subject to U.S. federal and most state income taxes. Any taxable income or loss generated by RMR LLC is passed through to and included in the taxable income or loss of its members, including RMR Inc. and ABP Trust, based on each member’s respective ownership percentage. For the three months ended June 30, 2023 and 2022, we recognized estimated income tax expense of $9,214 and $2,943, respectively, which includes $6,751 and $2,162, respectively, of U.S. federal income tax and $2,463 and $781, respectively, of state income taxes. For the nine months ended June 30, 2023 and 2022, we recognized estimated income tax expense of $18,581 and $8,448, respectively, which includes $13,614 and $6,205, respectively, of U.S. federal income tax and $4,967 and $2,243, respectively, of state income taxes. A reconciliation of the statutory income tax rate to the effective tax rate is as follows: Three Months Ended June 30, Nine Months Ended June 30, 2023 2022 2023 2022 Income taxes computed at the federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 3.1 % 3.1 % 3.0 % 3.1 % Permanent items 0.2 % 0.6 % 0.3 % 0.4 % Net income attributable to noncontrolling interest (10.0) % (10.1) % (9.9) % (10.1) % Total 14.3 % 14.6 % 14.4 % 14.4 % ASC 740, Income Taxes , provides a model for how a company should recognize, measure and present in its financial statements uncertain tax positions that have been taken or are expected to be taken with respect to all open years and in all significant jurisdictions. Pursuant to this topic, we recognize a tax benefit only if it is “more likely than not” that a particular tax position will be sustained upon examination or audit. To the extent the “more likely than not” standard has been satisfied, the benefit associated with a tax position is measured as the largest amount that is greater than 50.0% likely to be realized upon settlement. As of June 30, 2023 and 2022, we had no uncertain tax positions.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments As of June 30, 2023 and September 30, 2022, the fair values of our financial instruments, which include cash and cash equivalents, amounts due from related parties, accounts payable and accrued expenses and reimbursable accounts payable and accrued expenses, were not materially different from their carrying values due to the short term nature of these financial instruments. On a recurring basis, we measure certain financial assets and financial liabilities at fair value based upon quoted market prices. ASC 820, Fair Value Measurements , establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets and liabilities (Level 1), and the lowest priority to unobservable inputs (Level 3). A financial asset’s or financial liability’s fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The following table presents our assets and liabilities that have been measured at fair value using Level 1 inputs in the fair value hierarchy as of June 30, 2023 and September 30, 2022: June 30, September 30, 2023 2022 Current portion of due from related parties related to share based payment awards $ 1,039 $ 7,516 Long term portion of due from related parties related to share based payment awards 6,632 14,557 Equity method investment in SEVN 17,525 15,577 Equity method investment in TA — 33,537 Current portion of employer compensation liability related to share based payment awards 1,039 7,516 Long term portion of employer compensation liability related to share based payment awards 6,632 14,557

Related Person Transactions

Related Person Transactions	9 Months Ended
	Jun. 30, 2023
Related Party Transactions [Abstract]
Related Person Transactions	Related Person Transactions Adam D. Portnoy, Chair of our Board, one of our Managing Directors and our President and Chief Executive Officer, is the sole trustee of our controlling shareholder, ABP Trust, and owns all of ABP Trust’s voting securities and a majority of the economic interests of ABP Trust. RMR Inc.’s other executive officers are officers and employees of RMR LLC, and Jennifer B. Clark, our other Managing Director, and Matthew P. Jordan, our Executive Vice President, Chief Financial Officer and Treasurer, are also officers of ABP Trust. Mr. Portnoy is the chair of the board and a managing trustee of each of the Perpetual Capital clients, the controlling shareholder and a director of Sonesta (and its parent) and was the chair of the board and a managing director of AlerisLife until March 20, 2023 when AlerisLife was acquired by ABP Trust. Since March 20, 2023, Mr. Portnoy is the sole director of AlerisLife. Mr. Portnoy was the chair of the board and a managing director of TA until May 15, 2023 when TA was acquired by BP. Ms. Clark is a managing trustee of OPI and a director of Sonesta (and its parent), and she previously served as a managing director of AlerisLife until March 20, 2023. Ms. Clark also serves as the secretary of all the Perpetual Capital clients, Sonesta and AlerisLife. As of June 30, 2023, Adam D. Portnoy beneficially owned 13.5% of SEVN’s outstanding common shares (including through Tremont and ABP Trust) and 9.8% of DHC’s outstanding common shares (including through ABP Trust). In addition, Mr. Portnoy beneficially owns shares of ILPT, OPI, SVC, and prior to May 15, 2023, TA, comprising less than 5.0% of the outstanding shares of each of those respective companies. The Managed Equity REITs and SEVN have no employees. RMR LLC provides or arranges for all the personnel, overhead and services required for the operation of the Managed Equity REITs pursuant to management agreements with them. The officers of the Managed Equity REITs and ABP Trust are officers or employees of RMR LLC. All the officers, overhead and required office space of SEVN are provided or arranged by Tremont. SEVN’s officers are officers or employees of Tremont or RMR LLC. Some of the executive officers of TA (prior to May 15, 2023), AlerisLife and Sonesta are officers or employees of RMR LLC. Our executive officers are also managing trustees of certain of the Perpetual Capital clients. Additional information about our related person transactions appears in Note 7, Shareholders’ Equity , below and in our 2022 Annual Report. Revenues from Related Parties For the three months ended June 30, 2023 and 2022, we recognized revenues from related parties as set forth in the following table: Three Months Ended June 30, 2023 Three Months Ended June 30, 2022 Total Total Management Management and Advisory Total and Advisory Total Services Reimbursable Total Services Reimbursable Total Revenues Costs Revenues Revenues Costs Revenues Perpetual Capital: DHC $ 5,655 $ 37,352 $ 43,007 $ 7,208 $ 41,318 $ 48,526 ILPT 9,113 10,664 19,777 9,803 8,126 17,929 OPI 9,363 89,220 98,583 10,640 80,083 90,723 SVC 10,308 34,643 44,951 10,721 10,412 21,133 Total Managed Equity REITs 34,439 171,879 206,318 38,372 139,939 178,311 SEVN 1,333 1,193 2,526 1,137 1,006 2,143 TA (1) 47,238 — 47,238 4,441 527 4,968 83,010 173,072 256,082 43,950 141,472 185,422 Private Capital: AlerisLife (2) 1,381 — 1,381 1,239 99 1,338 Sonesta 2,796 — 2,796 2,491 46 2,537 Other private entities 5,248 14,666 19,914 5,230 16,515 21,745 9,425 14,666 24,091 8,960 16,660 25,620 Total revenues from related parties 92,435 187,738 280,173 52,910 158,132 211,042 Revenues from unrelated parties 52 — 52 46 — 46 Total revenues $ 92,487 $ 187,738 $ 280,225 $ 52,956 $ 158,132 $ 211,088 (1) On May 15, 2023, BP acquired TA and TA terminated its management agreement with us. In connection with the termination of TA’s management agreement, we received the applicable termination fee of $45,282. For further information, please see “TA Merger” below. (2) On March 20, 2023, AlerisLife merged with and into a subsidiary of ABP Trust and ceased to be a public company. As a result, the revenues earned with respect to AlerisLife are characterized as Private Capital for all periods presented. For further information about this transaction, please see “ ABP Trust’s Acquisition of AlerisLife ” below. For the nine months ended June 30, 2023 and 2022, we recognized revenues from related parties as set forth in the following table: Nine Months Ended June 30, 2023 Nine Months Ended June 30, 2022 Total Total Management Management and Advisory Total and Advisory Total Services Reimbursable Total Services Reimbursable Total Revenues Costs Revenues Revenues Costs Revenues Perpetual Capital: (1) DHC $ 17,593 $ 117,821 $ 135,414 $ 23,737 $ 109,241 $ 132,978 ILPT 27,377 30,615 57,992 21,545 20,387 41,932 OPI 29,448 268,204 297,652 31,722 221,249 252,971 SVC 30,046 75,468 105,514 34,113 43,641 77,754 Total Managed Equity REITs 104,464 492,108 596,572 111,117 394,518 505,635 SEVN 3,563 3,516 7,079 3,392 4,563 7,955 TA (2) 55,214 3,476 58,690 11,499 1,235 12,734 163,241 499,100 662,341 126,008 400,316 526,324 Private Capital: (1) AlerisLife (3) 4,014 97 4,111 3,610 245 3,855 Sonesta 6,954 544 7,498 6,092 84 6,176 Other private entities 16,074 49,308 65,382 12,450 41,406 53,856 27,042 49,949 76,991 22,152 41,735 63,887 Total revenues from related parties 190,283 549,049 739,332 148,160 442,051 590,211 Revenues from unrelated parties 52 — 52 99 — 99 Total revenues $ 190,335 $ 549,049 $ 739,384 $ 148,259 $ 442,051 $ 590,310 (1) On December 23, 2021, DHC sold a 35% equity interest in its existing joint venture with an institutional investor. Following this sale, DHC owned a 20% equity interest in this joint venture. As a result, the revenues earned with respect to this joint venture are characterized as Private Capital for periods on and after December 23, 2021 and as Perpetual Capital for periods prior to December 23, 2021. On June 29, 2022, DHC sold an additional 10% equity interest in this joint venture. Following this additional sale, DHC owns a 10% equity interest in this joint venture. (2) On May 15, 2023, BP acquired TA and TA terminated its management agreement with us. In connection with the termination of TA’s management agreement, we received the applicable termination fee of $45,282. For further information, please see “TA Merger” below. (3) On March 20, 2023, AlerisLife merged with and into a subsidiary of ABP Trust and ceased to be a public company. As a result, the revenues earned with respect to AlerisLife are characterized as Private Capital for all periods presented. For further information about this transaction, please see “ ABP Trust’s Acquisition of AlerisLife ” below. Amounts Due From Related Parties The following table presents amounts due from related parties as of the dates indicated: June 30, 2023 September 30, 2022 Accounts Reimbursable Accounts Reimbursable Receivable Costs Total Receivable Costs Total Perpetual Capital: DHC $ 4,692 $ 15,525 $ 20,217 $ 8,098 $ 14,148 $ 22,246 ILPT 3,928 7,739 11,667 3,235 13,717 16,952 OPI 6,125 45,206 51,331 335 47,943 48,278 SVC 4,640 6,096 10,736 5,627 5,357 10,984 Total Managed Equity REITs 19,385 74,566 93,951 17,295 81,165 98,460 SEVN 3,115 1,433 4,548 1,768 1,262 3,030 TA (1) — — — 124 11,635 11,759 22,500 75,999 98,499 19,187 94,062 113,249 Private Capital: AlerisLife (2) 68 — 68 112 492 604 Sonesta 65 — 65 127 290 417 Other private entities 4,166 5,935 10,101 1,658 7,450 9,108 4,299 5,935 10,234 1,897 8,232 10,129 $ 26,799 $ 81,934 $ 108,733 $ 21,084 $ 102,294 $ 123,378 (1) On May 15, 2023, BP acquired TA and TA terminated its management agreement with us. For further information about this transaction, please see “TA Merger” below. (2) On March 20, 2023, AlerisLife merged with and into a subsidiary of ABP Trust and ceased to be a public company. As a result, the amounts due from related parties with respect to AlerisLife are characterized as Private Capital for all periods presented. For further information about this transaction, please see “ ABP Trust’s Acquisition of AlerisLife ” below. Leases As of June 30, 2023, RMR LLC leased from ABP Trust and certain Managed Equity REITs office space for use as our headquarters and local offices. We incurred rental expense under related party leases aggregating $1,221 and $1,470 for the three months ended June 30, 2023 and 2022, respectively, and $4,052 and $4,444 for the nine months ended June 30, 2023 and 2022, respectively. Tax-Related Payments Pursuant to our tax receivable agreement with ABP Trust, RMR Inc. pays to ABP Trust 85.0% of the amount of cash savings, if any, in U.S. federal, state and local income tax or franchise tax that RMR Inc. realizes as a result of (a) the increases in tax basis attributable to our dealings with ABP Trust and (b) tax benefits related to imputed interest deemed to be paid by us as a result of the tax receivable agreement. As of June 30, 2023, our condensed consolidated balance sheet reflects a liability related to the tax receivable agreement of $25,583, including $2,275 classified as a current liability in accounts payable and accrued expenses that we expect to pay to ABP Trust during the fourth quarter of fiscal year 2023. Under the RMR LLC operating agreement, RMR LLC is also required to make certain pro rata distributions to each member of RMR LLC quarterly on the basis of the estimated tax liabilities of its members, subject to future adjustment based on actual results. For the nine months ended June 30, 2023 and 2022, pursuant to the RMR LLC operating agreement, RMR LLC made required quarterly tax distributions to holders of its membership units totaling $48,857 and $21,969, respectively, of which $25,758 and $11,559, respectively, was distributed to us and $23,099 and $10,410, respectively, was distributed to ABP Trust, based on each membership unit holder’s respective ownership percentage. The amounts distributed to us were eliminated in our condensed consolidated financial statements, and the amounts distributed to ABP Trust were recorded as a reduction of its noncontrolling interest. We use funds from these distributions to pay certain of our U.S. federal and state income tax liabilities and to pay part of our obligations under the tax receivable agreement. Purchase of SEVN Shares On May 11, 2022, Tremont Realty Capital purchased 882,407 SEVN common shares of beneficial interest from Diane Portnoy, the mother of Adam D. Portnoy, for an aggregate purchase price of $9,469. As of June 30, 2023, Tremont owned 1,708,058 SEVN common shares, and Mr. Portnoy beneficially owned 13.5% of SEVN’s outstanding common shares of beneficial interest (including through Tremont and ABP Trust). ABP Trust’s Acquisition of AlerisLife On March 20, 2023, ABP Trust acquired AlerisLife. In connection with that acquisition, AlerisLife terminated its management agreement with RMR LLC and RMR LLC waived its right to receive payment of the termination fee that would have otherwise resulted due to the acquisition. In consideration of this waiver, RMR LLC and ABP Trust amended and restated their management agreement to provide that (i) RMR LLC will also provide services to AlerisLife at ABP Trust’s request, (ii) ABP Trust will pay to RMR LLC management fees with respect to AlerisLife, which fees are calculated based upon AlerisLife’s revenues in the same manner as such fees would have been calculated under AlerisLife’s terminated management agreement with RMR LLC, and (iii) AlerisLife’s properties will not be subject to ABP Trust’s property management agreement with RMR LLC. TA Merger On May 15, 2023, BP acquired TA in a merger transaction for $86.00 per TA common share in cash, or the TA Merger. RMR LLC received $53,479 for its TA common shares pursuant to that acquisition. In connection with that acquisition, RMR LLC, which owned an aggregate amount of 4.1% of TA’s outstanding common shares, entered into a voting agreement with BP pursuant to which RMR LLC agreed to vote all of its TA common shares to approve the transaction. Upon consummation of the acquisition, TA terminated its business management agreement with us and in accordance with its terms paid us the applicable termination fee of $45,282. OPI’s Merger Agreement with DHC On April 11, 2023, DHC and OPI entered into an Agreement and Plan of Merger, or the DHC-OPI Merger Agreement, pursuant to which, on the terms and subject to the satisfaction or waiver of the conditions thereof, DHC will be merged with and into OPI, with OPI continuing as the surviving entity in the merger, or the DHC-OPI Merger. The DHC-OPI Merger is expected to close during the third quarter of calendar 2023. Contemporaneously with the execution of the DHC-OPI Merger Agreement, we, DHC and OPI entered into a letter agreement, or the RMR Letter Agreement, pursuant to which, on the terms and subject to conditions contained therein, we and DHC have acknowledged and agreed that, effective upon consummation of the DHC-OPI Merger, DHC shall have terminated its business and property management agreements with us for convenience, and we shall have waived our right to receive payment of the termination fee pursuant to each such agreement upon such termination. We will continue to manage the surviving entity following the DHC-OPI Merger. Contemporaneously with the execution of the DHC-OPI Merger Agreement, RMR LLC and OPI entered into a Third Amended and Restated Property Management Agreement, or the Amended Property Management Agreement. The effectiveness of the Amended Property Management Agreement is conditioned upon and will be concurrent with the consummation of the DHC-OPI Merger. Pursuant to the Amended Property Management Agreement, at the effective time of the DHC-OPI Merger, properties then owned by DHC that are subject to its existing property management agreement with RMR LLC, including its medical office and life science properties, will become subject to the terms and conditions of the Amended Property Management Agreement. Also pursuant to the Amended Property Management Agreement, we will be entitled to a renovation and repositioning fee equal to 3% of the cost of any major capital projects and repositionings at senior living communities owned by DHC that the surviving entity may request us to oversee from time to time, consistent with DHC’s existing property management agreement. The terms of the Amended Property Management Agreement are otherwise consistent with the terms of RMR LLC’s existing property management agreement with OPI. Separation Arrangements We entered into retirement agreements with certain of our former executive officers. Pursuant to these agreements, we made various cash payments and accelerated the vesting of unvested shares of RMR Inc. previously awarded to these retiring officers. We also enter into separation arrangements from time to time with executive and nonexecutive officers and employees of ours. All costs associated with separation arrangements, for which there remain no substantive performance obligations, are recorded in our condensed consolidated statements of income as separation costs. RMR LLC entered into a letter agreement, or the Separation Agreement, dated March 27, 2023, with Jonathan M. Pertchik, a former Executive Vice President of RMR LLC. Mr. Pertchik also served as chief executive officer and was a managing director of TA. Mr. Pertchik resigned as our Executive Vice President, effective 11:59 p.m. on May 14, 2023, the date prior to the closing of the TA Merger, or the Separation Date. Pursuant to the Separation Agreement, RMR LLC paid Mr. Pertchik $211 following the TA Merger and our Compensation Committee approved the acceleration of vesting of Mr. Pertchik’s unvested shares of RMR Inc., effective as of the Separation Date. The Separation Agreement contains other customary terms and conditions, including confidentiality, non-solicitation, and other covenants and a waiver and release. For the three months ended June 30, 2023 and 2022, we recognized separation costs of $1,064 and $400, respectively, including cash separation costs of $708 and $252, respectively, and equity based separation costs of $356 and $148, respectively. For the nine months ended June 30, 2023 and 2022, we recognized separation costs of $2,002 and $617, respectively, including cash separation costs of $1,520 and $469, respectively, and equity based separation costs of $482 and $148, respectively. SEVN Property Management Agreement We entered into a new property management agreement with SEVN in July 2023 with respect to an office property SEVN owns. Pursuant to this agreement, we will provide property management services and SEVN will pay us fees equal to 3.0% of gross collected rents. Also under the terms of this property management agreement, SEVN will pay us additional fees for construction supervision services equal to 5.0% of the cost of such construction. Either we or SEVN may terminate this agreement upon 30 days’ prior notice. No termination fee would be payable as a result of terminating the agreement.

Shareholders_ Equity

Shareholders’ Equity	9 Months Ended
	Jun. 30, 2023
Stockholders' Equity Note [Abstract]
Shareholders’ Equity	Shareholders’ Equity We award our Class A common stock, or Class A Common Shares, to our Directors, officers and employees under the Amended and Restated 2016 Omnibus Equity Plan, or the 2016 Plan. Director share awards vest immediately. Officer and employee share awards vest in five equal, consecutive, annual installments, with the first installment vesting on the date of award. We recognize forfeitures as they occur. Compensation expense related to share awards is determined based on the market value of our shares on the date of award, with the aggregate value of the awarded shares amortized to expense over the related vesting period. Expense recognized for Director share awards are included in general and administrative expenses and expense recognized for officer and employee share awards are included in equity based compensation in our condensed consolidated statements of income. On March 29, 2023, we awarded 3,000 of our Class A Common Shares, valued at $25.80 per share, the closing price of our Class A Common Shares on The Nasdaq Stock Market LLC, or Nasdaq, on that day, to each of our Directors as part of his or her annual compensation for serving as a Director. For the nine months ended June 30, 2023, we recorded general and administrative expense of $464 for these awards. Equity based compensation expense related to shares awarded to certain officers and employees was $478 and $581 for the three months ended June 30, 2023 and 2022, respectively, and $1,576 and $1,823 for the nine months ended June 30, 2023 and 2022, respectively. As of June 30, 2023, we had 170,420 unvested shares outstanding which are scheduled to vest as follows: 62,160 shares in 2023, 49,920 shares in 2024, 36,740 shares in 2025 and 21,600 in 2026. In connection with the vesting and issuance of awards of our Class A Common Shares to our Directors, officers and employees, we provide for the ability to repurchase our Class A Common Shares to satisfy tax withholding and payment obligations for those eligible to do so. The repurchase price is based on the closing price of our Class A Common Shares on Nasdaq on the date of repurchase. The aggregate value of 7,383 Class A Common Shares repurchased during the nine months ended June 30, 2023 was $179, which is recorded as a decrease to additional paid in capital within shareholders’ equity in our condensed consolidated balance sheets. In connection with the issuances and repurchases of our Class A Common Shares, and as required by the RMR LLC operating agreement, RMR LLC concurrently issues or acquires an identical number of Class A Units from RMR Inc. Distributions During the nine months ended June 30, 2023 and 2022, we declared and paid dividends on our Class A Common Shares and Class B-1 common stock, or Class B-1 Common Shares, as follows: Declaration Record Paid Distributions Total Date Date Date Per Common Share Distributions Nine Months Ended June 30, 2023 10/13/2022 10/24/2022 11/17/2022 $ 0.40 $ 6,642 1/12/2023 1/23/2023 2/16/2023 0.40 6,641 4/13/2023 4/24/2023 5/18/2023 0.40 6,648 $ 1.20 $ 19,931 Nine Months Ended June 30, 2022 10/14/2021 10/25/2021 11/18/2021 $ 0.38 $ 6,264 1/13/2022 1/24/2022 2/17/2022 0.38 6,265 4/14/2022 4/25/2022 5/19/2022 0.40 6,601 $ 1.16 $ 19,130 These dividends were funded in part by distributions from RMR LLC to holders of its membership units as follows: Distributions Per Total RMR LLC RMR LLC Declaration Record Paid RMR LLC RMR LLC Distributions Distributions Date Date Date Membership Unit Distributions to RMR Inc. to ABP Trust Nine Months Ended June 30, 2023 10/13/2022 10/24/2022 11/17/2022 $ 0.32 $ 10,114 $ 5,314 $ 4,800 1/12/2023 1/23/2023 2/16/2023 0.32 10,113 5,313 4,800 4/13/2023 4/24/2023 5/18/2023 0.32 10,118 5,318 4,800 $ 0.96 $ 30,345 $ 15,945 $ 14,400 Nine Months Ended June 30, 2022 10/14/2021 10/25/2021 11/18/2021 $ 0.30 $ 9,446 $ 4,946 $ 4,500 1/13/2022 1/24/2022 2/17/2022 0.30 9,446 4,946 4,500 4/14/2022 4/25/2022 5/19/2022 0.32 10,080 5,280 4,800 $ 0.92 $ 28,972 $ 15,172 $ 13,800 The remainder of the dividends noted above were funded with cash accumulated at RMR Inc. On July 13, 2023, we declared a quarterly dividend on our Class A Common Shares and Class B-1 Common Shares to our shareholders of record as of July 24, 2023, in the amount of $0.40 per Class A Common Share and Class B-1 Common Share, or $6,645. This dividend will be partially funded by a distribution from RMR LLC to holders of its membership units in the amount of $0.32 per unit, or $10,116, of which $5,316 will be distributed to us based on our aggregate ownership of 16,613,279 membership units of RMR LLC and $4,800 will be distributed to ABP Trust based on its ownership of 15,000,000 membership units of RMR LLC. The remainder of this dividend will be funded with cash accumulated at RMR Inc. We expect to pay this dividend on or about August 17, 2023.

Per Common Share Amounts

Per Common Share Amounts	9 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Per Common Share Amounts	Per Common Share AmountsWe calculate basic earnings per share using the two-class method. Unvested Class A Common Shares awarded to our employees are deemed participating securities for purposes of calculating basic earnings per common share because they have dividend rights. Under the two-class method, we allocate earnings proportionately to vested Class A Common Shares and Class B-1 Common Shares outstanding and unvested Class A Common Shares outstanding for the period. Accordingly, earnings attributable to unvested Class A Common Shares are excluded from basic earnings per share under the two-class method. Our Class B-2 common stock of RMR Inc., or Class B-2 Common Shares, which are paired with ABP Trust’s Class A Units, have no independent economic interest in RMR Inc. and thus are not included as common shares outstanding for purposes of calculating basic earnings per common share. Diluted earnings per share is calculated using the treasury stock method for unvested Class A Common Shares and the if-converted method for Class B-2 Common Shares. The 15,000,000 Class A Units that we do not own may be redeemed for our Class A Common Shares on a one-for-one basis, or upon such redemption, we may elect to pay cash instead of issuing Class A Common Shares. Upon redemption of a Class A Unit, the Class B-2 Common Share “paired” with such unit is canceled for no additional consideration. In computing the dilutive effect, if any, that the assumed redemption would have on earnings per share, we considered that net income available to holders of our Class A Common Shares would increase due to elimination of the noncontrolling interest offset by any tax effect, which may be dilutive. For the three months ended June 30, 2022 and the nine months ended June 30, 2023 and 2022, the assumed redemption is dilutive to earnings per share. For the three months ended June 30, 2023, such redemption is not reflected in diluted earnings per share as the assumed redemption would be anti-dilutive. The calculation of basic and diluted earnings per share for the three and nine months ended June 30, 2023 and 2022, is as follows: Three Months Ended June 30, Nine Months Ended June 30, 2023 2022 2023 2022 Numerators: Net income attributable to The RMR Group Inc. $ 24,641 $ 7,570 $ 49,451 $ 22,004 Less: income attributable to unvested participating securities (273) (72) (580) (213) Net income attributable to The RMR Group Inc. used in calculating basic EPS 24,368 7,498 48,871 21,791 Effect of dilutive securities: Add back: income attributable to unvested participating securities — 72 580 213 Add back: net income attributable to noncontrolling interest — 9,695 61,262 28,142 Add back: income tax expense — 2,943 18,581 8,448 Less: income tax expense assuming redemption of noncontrolling interest’s Class A Units for Class A Common Shares (1) — (5,851) (35,932) (16,833) Net income used in calculating diluted EPS $ 24,368 $ 14,357 $ 93,362 $ 41,761 Denominators: Common shares outstanding 16,614 16,501 16,614 16,501 Less: unvested participating securities and incremental impact of weighted average (179) (158) (198) (169) Weighted average common shares outstanding - basic 16,435 16,343 16,416 16,332 Effect of dilutive securities: Add: assumed redemption of noncontrolling interest’s Class A Units for Class A Common Shares — 15,000 15,000 15,000 Add: incremental unvested shares — 10 15 10 Weighted average common shares outstanding - diluted 16,435 31,353 31,431 31,342 Net income attributable to The RMR Group Inc. per common share - basic $ 1.48 $ 0.46 $ 2.98 $ 1.33 Net income attributable to The RMR Group Inc. per common share - diluted $ 1.48 $ 0.46 $ 2.97 $ 1.33 (1) Income tax expense assumes the hypothetical conversion of the noncontrolling interest, which results in estimated tax rates of 29.0% for the three months ended June 30, 2022, and 27.8% and 28.7% for the nine months ended June 30, 2023 and 2022, respectively.

Net Income Attributable to RMR

Net Income Attributable to RMR Inc.	9 Months Ended
	Jun. 30, 2023
Net Income Attributable to RMR Inc.
Net Income Attributable to RMR Inc.	Net Income Attributable to RMR Inc. Net income attributable to RMR Inc. for the three and nine months ended June 30, 2023 and 2022, is calculated as follows: Three Months Ended June 30, Nine Months Ended June 30, 2023 2022 2023 2022 Income before income tax expense $ 64,385 $ 20,208 $ 129,294 $ 58,594 RMR Inc. franchise tax expense and interest income (110) 149 (255) 485 Net income before noncontrolling interest 64,275 20,357 129,039 59,079 Net income attributable to noncontrolling interest (30,530) (9,695) (61,262) (28,142) Net income attributable to RMR Inc. before income tax expense 33,745 10,662 67,777 30,937 Income tax expense attributable to RMR Inc. (9,214) (2,943) (18,581) (8,448) RMR Inc. franchise tax expense and interest income 110 (149) 255 (485) Net income attributable to RMR Inc. $ 24,641 $ 7,570 $ 49,451 $ 22,004

Subsequent Events

Subsequent Events	9 Months Ended
	Jun. 30, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On July 29, 2023, RMR LLC entered into an equity purchase agreement, or the Purchase Agreement, with MPC Partnership Holdings LLC, a Georgia limited liability company, or MPC. MPC, which does business as CARROLL, is a vertically-integrated platform focused on investing in multifamily properties in the Sun Belt region of the United States. Pursuant to the Purchase Agreement, and upon the terms and subject to the conditions thereof, RMR LLC will acquire all of the issued and outstanding equity interests of MPC for $80,000 in cash, subject to customary adjustments for cash, debt, transaction expenses, working capital, and property management revenue at closing, plus up to an additional $20,000 of contingent consideration subject to the deployment of capital remaining in investment funds managed by MPC prior to the end of such fund’s investment period. Consummation of the acquisition is subject to customary conditions, including, among others, (i) MPC obtaining all required consents with respect to managed funds, joint-venture investors and applicable lenders with respect to its managed properties, (ii) MPC’s revenues from its property management agreements at the time the acquisition is consummated being not less than 85% of an agreed upon baseline property management revenue and (iii) the absence of any Material Adverse Effect (as defined in the Purchase Agreement).

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Schedule of Reconciliation of the Statutory Income Tax Rate to the Effective Tax Rate	A reconciliation of the statutory income tax rate to the effective tax rate is as follows: Three Months Ended June 30, Nine Months Ended June 30, 2023 2022 2023 2022 Income taxes computed at the federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 3.1 % 3.1 % 3.0 % 3.1 % Permanent items 0.2 % 0.6 % 0.3 % 0.4 % Net income attributable to noncontrolling interest (10.0) % (10.1) % (9.9) % (10.1) % Total 14.3 % 14.6 % 14.4 % 14.4 %

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value	The following table presents our assets and liabilities that have been measured at fair value using Level 1 inputs in the fair value hierarchy as of June 30, 2023 and September 30, 2022: June 30, September 30, 2023 2022 Current portion of due from related parties related to share based payment awards $ 1,039 $ 7,516 Long term portion of due from related parties related to share based payment awards 6,632 14,557 Equity method investment in SEVN 17,525 15,577 Equity method investment in TA — 33,537 Current portion of employer compensation liability related to share based payment awards 1,039 7,516 Long term portion of employer compensation liability related to share based payment awards 6,632 14,557

Related Person Transactions (Ta

Related Person Transactions (Tables)	9 Months Ended
	Jun. 30, 2023
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	For the three months ended June 30, 2023 and 2022, we recognized revenues from related parties as set forth in the following table: Three Months Ended June 30, 2023 Three Months Ended June 30, 2022 Total Total Management Management and Advisory Total and Advisory Total Services Reimbursable Total Services Reimbursable Total Revenues Costs Revenues Revenues Costs Revenues Perpetual Capital: DHC $ 5,655 $ 37,352 $ 43,007 $ 7,208 $ 41,318 $ 48,526 ILPT 9,113 10,664 19,777 9,803 8,126 17,929 OPI 9,363 89,220 98,583 10,640 80,083 90,723 SVC 10,308 34,643 44,951 10,721 10,412 21,133 Total Managed Equity REITs 34,439 171,879 206,318 38,372 139,939 178,311 SEVN 1,333 1,193 2,526 1,137 1,006 2,143 TA (1) 47,238 — 47,238 4,441 527 4,968 83,010 173,072 256,082 43,950 141,472 185,422 Private Capital: AlerisLife (2) 1,381 — 1,381 1,239 99 1,338 Sonesta 2,796 — 2,796 2,491 46 2,537 Other private entities 5,248 14,666 19,914 5,230 16,515 21,745 9,425 14,666 24,091 8,960 16,660 25,620 Total revenues from related parties 92,435 187,738 280,173 52,910 158,132 211,042 Revenues from unrelated parties 52 — 52 46 — 46 Total revenues $ 92,487 $ 187,738 $ 280,225 $ 52,956 $ 158,132 $ 211,088 (1) On May 15, 2023, BP acquired TA and TA terminated its management agreement with us. In connection with the termination of TA’s management agreement, we received the applicable termination fee of $45,282. For further information, please see “TA Merger” below. (2) On March 20, 2023, AlerisLife merged with and into a subsidiary of ABP Trust and ceased to be a public company. As a result, the revenues earned with respect to AlerisLife are characterized as Private Capital for all periods presented. For further information about this transaction, please see “ ABP Trust’s Acquisition of AlerisLife ” below. For the nine months ended June 30, 2023 and 2022, we recognized revenues from related parties as set forth in the following table: Nine Months Ended June 30, 2023 Nine Months Ended June 30, 2022 Total Total Management Management and Advisory Total and Advisory Total Services Reimbursable Total Services Reimbursable Total Revenues Costs Revenues Revenues Costs Revenues Perpetual Capital: (1) DHC $ 17,593 $ 117,821 $ 135,414 $ 23,737 $ 109,241 $ 132,978 ILPT 27,377 30,615 57,992 21,545 20,387 41,932 OPI 29,448 268,204 297,652 31,722 221,249 252,971 SVC 30,046 75,468 105,514 34,113 43,641 77,754 Total Managed Equity REITs 104,464 492,108 596,572 111,117 394,518 505,635 SEVN 3,563 3,516 7,079 3,392 4,563 7,955 TA (2) 55,214 3,476 58,690 11,499 1,235 12,734 163,241 499,100 662,341 126,008 400,316 526,324 Private Capital: (1) AlerisLife (3) 4,014 97 4,111 3,610 245 3,855 Sonesta 6,954 544 7,498 6,092 84 6,176 Other private entities 16,074 49,308 65,382 12,450 41,406 53,856 27,042 49,949 76,991 22,152 41,735 63,887 Total revenues from related parties 190,283 549,049 739,332 148,160 442,051 590,211 Revenues from unrelated parties 52 — 52 99 — 99 Total revenues $ 190,335 $ 549,049 $ 739,384 $ 148,259 $ 442,051 $ 590,310 (1) On December 23, 2021, DHC sold a 35% equity interest in its existing joint venture with an institutional investor. Following this sale, DHC owned a 20% equity interest in this joint venture. As a result, the revenues earned with respect to this joint venture are characterized as Private Capital for periods on and after December 23, 2021 and as Perpetual Capital for periods prior to December 23, 2021. On June 29, 2022, DHC sold an additional 10% equity interest in this joint venture. Following this additional sale, DHC owns a 10% equity interest in this joint venture. (2) On May 15, 2023, BP acquired TA and TA terminated its management agreement with us. In connection with the termination of TA’s management agreement, we received the applicable termination fee of $45,282. For further information, please see “TA Merger” below. (3) On March 20, 2023, AlerisLife merged with and into a subsidiary of ABP Trust and ceased to be a public company. As a result, the revenues earned with respect to AlerisLife are characterized as Private Capital for all periods presented. For further information about this transaction, please see “ ABP Trust’s Acquisition of AlerisLife ” below. Amounts Due From Related Parties The following table presents amounts due from related parties as of the dates indicated: June 30, 2023 September 30, 2022 Accounts Reimbursable Accounts Reimbursable Receivable Costs Total Receivable Costs Total Perpetual Capital: DHC $ 4,692 $ 15,525 $ 20,217 $ 8,098 $ 14,148 $ 22,246 ILPT 3,928 7,739 11,667 3,235 13,717 16,952 OPI 6,125 45,206 51,331 335 47,943 48,278 SVC 4,640 6,096 10,736 5,627 5,357 10,984 Total Managed Equity REITs 19,385 74,566 93,951 17,295 81,165 98,460 SEVN 3,115 1,433 4,548 1,768 1,262 3,030 TA (1) — — — 124 11,635 11,759 22,500 75,999 98,499 19,187 94,062 113,249 Private Capital: AlerisLife (2) 68 — 68 112 492 604 Sonesta 65 — 65 127 290 417 Other private entities 4,166 5,935 10,101 1,658 7,450 9,108 4,299 5,935 10,234 1,897 8,232 10,129 $ 26,799 $ 81,934 $ 108,733 $ 21,084 $ 102,294 $ 123,378 (1) On May 15, 2023, BP acquired TA and TA terminated its management agreement with us. For further information about this transaction, please see “TA Merger” below. (2) On March 20, 2023, AlerisLife merged with and into a subsidiary of ABP Trust and ceased to be a public company. As a result, the amounts due from related parties with respect to AlerisLife are characterized as Private Capital for all periods presented. For further information about this transaction, please see “ ABP Trust’s Acquisition of AlerisLife ” below.

Shareholders_ Equity (Tables)

Shareholders’ Equity (Tables)	9 Months Ended
	Jun. 30, 2023
Stockholders' Equity Note [Abstract]
Schedule of Dividends Declared	During the nine months ended June 30, 2023 and 2022, we declared and paid dividends on our Class A Common Shares and Class B-1 common stock, or Class B-1 Common Shares, as follows: Declaration Record Paid Distributions Total Date Date Date Per Common Share Distributions Nine Months Ended June 30, 2023 10/13/2022 10/24/2022 11/17/2022 $ 0.40 $ 6,642 1/12/2023 1/23/2023 2/16/2023 0.40 6,641 4/13/2023 4/24/2023 5/18/2023 0.40 6,648 $ 1.20 $ 19,931 Nine Months Ended June 30, 2022 10/14/2021 10/25/2021 11/18/2021 $ 0.38 $ 6,264 1/13/2022 1/24/2022 2/17/2022 0.38 6,265 4/14/2022 4/25/2022 5/19/2022 0.40 6,601 $ 1.16 $ 19,130 These dividends were funded in part by distributions from RMR LLC to holders of its membership units as follows: Distributions Per Total RMR LLC RMR LLC Declaration Record Paid RMR LLC RMR LLC Distributions Distributions Date Date Date Membership Unit Distributions to RMR Inc. to ABP Trust Nine Months Ended June 30, 2023 10/13/2022 10/24/2022 11/17/2022 $ 0.32 $ 10,114 $ 5,314 $ 4,800 1/12/2023 1/23/2023 2/16/2023 0.32 10,113 5,313 4,800 4/13/2023 4/24/2023 5/18/2023 0.32 10,118 5,318 4,800 $ 0.96 $ 30,345 $ 15,945 $ 14,400 Nine Months Ended June 30, 2022 10/14/2021 10/25/2021 11/18/2021 $ 0.30 $ 9,446 $ 4,946 $ 4,500 1/13/2022 1/24/2022 2/17/2022 0.30 9,446 4,946 4,500 4/14/2022 4/25/2022 5/19/2022 0.32 10,080 5,280 4,800 $ 0.92 $ 28,972 $ 15,172 $ 13,800

Per Common Share Amounts (Table

Per Common Share Amounts (Tables)	9 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Schedule of Earnings Per Share	The calculation of basic and diluted earnings per share for the three and nine months ended June 30, 2023 and 2022, is as follows: Three Months Ended June 30, Nine Months Ended June 30, 2023 2022 2023 2022 Numerators: Net income attributable to The RMR Group Inc. $ 24,641 $ 7,570 $ 49,451 $ 22,004 Less: income attributable to unvested participating securities (273) (72) (580) (213) Net income attributable to The RMR Group Inc. used in calculating basic EPS 24,368 7,498 48,871 21,791 Effect of dilutive securities: Add back: income attributable to unvested participating securities — 72 580 213 Add back: net income attributable to noncontrolling interest — 9,695 61,262 28,142 Add back: income tax expense — 2,943 18,581 8,448 Less: income tax expense assuming redemption of noncontrolling interest’s Class A Units for Class A Common Shares (1) — (5,851) (35,932) (16,833) Net income used in calculating diluted EPS $ 24,368 $ 14,357 $ 93,362 $ 41,761 Denominators: Common shares outstanding 16,614 16,501 16,614 16,501 Less: unvested participating securities and incremental impact of weighted average (179) (158) (198) (169) Weighted average common shares outstanding - basic 16,435 16,343 16,416 16,332 Effect of dilutive securities: Add: assumed redemption of noncontrolling interest’s Class A Units for Class A Common Shares — 15,000 15,000 15,000 Add: incremental unvested shares — 10 15 10 Weighted average common shares outstanding - diluted 16,435 31,353 31,431 31,342 Net income attributable to The RMR Group Inc. per common share - basic $ 1.48 $ 0.46 $ 2.98 $ 1.33 Net income attributable to The RMR Group Inc. per common share - diluted $ 1.48 $ 0.46 $ 2.97 $ 1.33 (1) Income tax expense assumes the hypothetical conversion of the noncontrolling interest, which results in estimated tax rates of 29.0% for the three months ended June 30, 2022, and 27.8% and 28.7% for the nine months ended June 30, 2023 and 2022, respectively.

Net Income Attributable to RM_2

Net Income Attributable to RMR Inc. (Tables)	9 Months Ended
	Jun. 30, 2023
Net Income Attributable to RMR Inc.
Schedule of Net Income Attributable to Parent	Net income attributable to RMR Inc. for the three and nine months ended June 30, 2023 and 2022, is calculated as follows: Three Months Ended June 30, Nine Months Ended June 30, 2023 2022 2023 2022 Income before income tax expense $ 64,385 $ 20,208 $ 129,294 $ 58,594 RMR Inc. franchise tax expense and interest income (110) 149 (255) 485 Net income before noncontrolling interest 64,275 20,357 129,039 59,079 Net income attributable to noncontrolling interest (30,530) (9,695) (61,262) (28,142) Net income attributable to RMR Inc. before income tax expense 33,745 10,662 67,777 30,937 Income tax expense attributable to RMR Inc. (9,214) (2,943) (18,581) (8,448) RMR Inc. franchise tax expense and interest income 110 (149) 255 (485) Net income attributable to RMR Inc. $ 24,641 $ 7,570 $ 49,451 $ 22,004

Basis of Presentation (Details)

Basis of Presentation (Details)	9 Months Ended
	Jun. 30, 2023 real_estate_investment_trust shares
Related Party Transaction [Line Items]
Number of managed trusts | real_estate_investment_trust	4
RMR LLC
Related Party Transaction [Line Items]
Ownership percentage	52.60%
Class B Membership Units
Related Party Transaction [Line Items]
Membership units (in shares)	1,000,000
Class A Common Stock | Class A Membership Units
Related Party Transaction [Line Items]
Membership units (in shares)	15,614,152
Capital Unit Redeemable Class A Units | ABP Trust
Related Party Transaction [Line Items]
Membership units (in shares)	15,000,000
Capital Unit Redeemable Class A Units | ABP Trust | RMR LLC
Related Party Transaction [Line Items]
Ownership percentage	47.40%

Revenue Recognition - Managemen

Revenue Recognition - Management Agreements with the Managed Equity REITs (Details) - Managed Equity REITs - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2022	Sep. 30, 2021
Business Management and Incentive Fees
Business management fees as a percentage of transferred real estate assets			0.50%
Business management fees as a percentage of average invested capital below the threshold limit			0.70%
Maximum threshold amount for calculating the business management fees	$ 250,000,000		$ 250,000,000
Business management fees as a percentage of average invested capital above the threshold limit			0.50%
Minimum threshold amount for calculating the business management fees	250,000,000		$ 250,000,000
Business management fees as a percent of average market capitalization below the threshold limit			0.70%
Business management fees as a percent of average market capitalization above the threshold limit			0.50%
Aggregate base business management fees	$ 21,037,000	$ 25,446,000	$ 63,894,000	$ 73,085,000
Contingent incentive business management fee percentage			12%
Aggregate incentive business management fees					$ 0	$ 0

Revenue Recognition - Other Man

Revenue Recognition - Other Management Agreements (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	May 15, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Related Party Transaction [Line Items]
received termination fees from TA		$ 280,225	$ 211,088	$ 739,384	$ 590,310
Termination and incentive business management fees
Related Party Transaction [Line Items]
received termination fees from TA	$ 45,282
Managed Operating Companies
Related Party Transaction [Line Items]
Business management fee percent based on management agreements				0.60%
Perpetual Capital
Related Party Transaction [Line Items]
Aggregate business management fees		9,134	11,107	$ 29,874	28,296
received termination fees from TA		$ 256,082	$ 185,422	$ 662,341	$ 526,324

Revenue Recognition - Property

Revenue Recognition - Property Management Fees (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue Recognition [Abstract]
Property management fee percent based on gross collected rents			3%
Property management fee percent based on the cost of construction			5%
Aggregate property management fees	$ 15,649	$ 15,220	$ 47,670	$ 43,387
Construction supervision fees	$ 4,418	$ 4,596	$ 14,120	$ 11,623

Revenue Recognition - Managem_2

Revenue Recognition - Management Agreements with Advisory Clients (Details) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Related Party Transaction [Line Items]
Total revenues	$ 280,225,000	$ 211,088,000	$ 739,384,000	$ 590,310,000
Tremont Advisors
Related Party Transaction [Line Items]
Incentive fee percentage condition 1			20%
Incentive fee percentage condition 2			7%
Tremont Advisors | Minimum
Related Party Transaction [Line Items]
Advisory fee percentage based on aggregate principal amounts of loan originate			0.50%
Tremont Advisors | Maximum
Related Party Transaction [Line Items]
Advisory fee percentage based on aggregate principal amounts of loan originate			1%
Advisory services
Related Party Transaction [Line Items]
Total revenues	1,141,000	1,137,000	$ 3,371,000	3,392,000
Advisory services | Tremont Advisors
Related Party Transaction [Line Items]
Business management fee percent based on management agreements			1.50%
Total revenues	1,141,000	1,137,000	$ 3,371,000	3,392,000
Management services
Related Party Transaction [Line Items]
Total revenues	45,872,000	51,819,000	141,490,000	144,867,000
Incentive fees | Tremont Advisors
Related Party Transaction [Line Items]
Total revenues	192,000	0	192,000	0
Tremont Advisors | Management services
Related Party Transaction [Line Items]
Total revenues	$ 52,000	$ 46,000	$ 52,000	$ 99,000

Equity Method Investments (Deta

Equity Method Investments (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	May 15, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Mar. 31, 2023	Sep. 30, 2022
Schedule of Equity Method Investments [Line Items]
Equity method investments accounted for under the fair value option		$ 17,525		$ 17,525			$ 49,114
Gain (loss) on equity method investments accounted for under the fair value option		663	$ (5,489)	23,513	$ (8,853)
Distributions from equity method investments				1,623	415
Proceeds from sale of TravelCenters of America Inc. common shares				53,479	0
SEVN
Schedule of Equity Method Investments [Line Items]
Gain (loss) on equity method investments accounted for under the fair value option		974	(209)	3,571	675
Distributions from equity method investments		598	207	1,623	415
SEVN | Level 1 | Recurring basis
Schedule of Equity Method Investments [Line Items]
Equity method investments accounted for under the fair value option		17,525		17,525			15,577
TA
Schedule of Equity Method Investments [Line Items]
Gain (loss) on equity method investments accounted for under the fair value option		(311)	$ 5,280	19,942	$ (9,528)
Proceeds from sale of TravelCenters of America Inc. common shares	$ 53,479
Equity method investment, realized gain (loss) on disposal	$ 39,778
TA | Level 1 | Recurring basis
Schedule of Equity Method Investments [Line Items]
Equity method investments accounted for under the fair value option		$ 0		$ 0			$ 33,537
Tremont Reality Capital | SEVN
Schedule of Equity Method Investments [Line Items]
Ownership percentage		11.60%		11.60%
RMR LLC | TA
Schedule of Equity Method Investments [Line Items]
Number of shares owned (in shares)						621,853
Ownership percentage						4.10%
Purchase price						$ 13,701
BP Products North America Inc | TA
Schedule of Equity Method Investments [Line Items]
Business acquisition share price (in dollars per share)	$ 86

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Income tax expense	$ 9,214	$ 2,943	$ 18,581	$ 8,448
Federal income tax expense	6,751	2,162	13,614	6,205
State income tax expense	$ 2,463	$ 781	$ 4,967	$ 2,243

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Tax Rate (Details)	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Income taxes computed at the federal statutory rate	21%	21%	21%	21%
State taxes, net of federal benefit	3.10%	3.10%	3%	3.10%
Permanent items	0.20%	0.60%	0.30%	0.40%
Net income attributable to noncontrolling interest	(10.00%)	(10.10%)	(9.90%)	(10.10%)
Total	14.30%	14.60%	14.40%	14.40%

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Schedule of assets and liabilities measured at fair value
Equity method investment	$ 17,525	$ 49,114
Recurring basis | Level 1
Schedule of assets and liabilities measured at fair value
Current portion of due from related parties related to share based payment awards	1,039	7,516
Long term portion of due from related parties related to share based payment awards	6,632	14,557
Current portion of employer compensation liability related to share based payment awards	1,039	7,516
Long term portion of employer compensation liability related to share based payment awards	6,632	14,557
Recurring basis | Level 1 | SEVN
Schedule of assets and liabilities measured at fair value
Equity method investment	17,525	15,577
Recurring basis | Level 1 | TA
Schedule of assets and liabilities measured at fair value
Equity method investment	$ 0	$ 33,537

Related Person Transactions - N

Related Person Transactions - Narrative (Details) - Related Party - Adam D. Portnoy	Jun. 30, 2023
SEVN
Related Party Transaction [Line Items]
Ownership percentage (less than)	13.50%
DHC
Related Party Transaction [Line Items]
Ownership percentage (less than)	9.80%
ILPT
Related Party Transaction [Line Items]
Ownership percentage (less than)	5%
OPI
Related Party Transaction [Line Items]
Ownership percentage (less than)	5%
SVC
Related Party Transaction [Line Items]
Ownership percentage (less than)	5%
TA
Related Party Transaction [Line Items]
Ownership percentage (less than)	5%

Related Person Transactions - R

Related Person Transactions - Revenues from Related Parties (Details) - USD ($) $ in Thousands			3 Months Ended		9 Months Ended
	Jun. 29, 2022	Dec. 23, 2021	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Related Party Transaction [Line Items]
Total revenues			$ 280,225	$ 211,088	$ 739,384	$ 590,310
DHC | Joint Venture With Institutional Investor
Related Party Transaction [Line Items]
Percentage of ownership sold	10%	35%
Ownership percentage	10%	20%
Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			92,487	52,956	190,335	148,259
Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			187,738	158,132	549,049	442,051
Related Party
Related Party Transaction [Line Items]
Total revenues			280,173	211,042	739,332	590,211
Related Party | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			92,435	52,910	190,283	148,160
Related Party | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			187,738	158,132	549,049	442,051
Perpetual Capital
Related Party Transaction [Line Items]
Total revenues			256,082	185,422	662,341	526,324
Perpetual Capital | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			83,010	43,950	163,241	126,008
Perpetual Capital | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			173,072	141,472	499,100	400,316
Managed Equity REITs
Related Party Transaction [Line Items]
Total revenues			206,318	178,311	596,572	505,635
Managed Equity REITs | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			34,439	38,372	104,464	111,117
Managed Equity REITs | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			171,879	139,939	492,108	394,518
DHC
Related Party Transaction [Line Items]
Total revenues			43,007	48,526	135,414	132,978
DHC | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			5,655	7,208	17,593	23,737
DHC | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			37,352	41,318	117,821	109,241
ILPT
Related Party Transaction [Line Items]
Total revenues			19,777	17,929	57,992	41,932
ILPT | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			9,113	9,803	27,377	21,545
ILPT | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			10,664	8,126	30,615	20,387
OPI
Related Party Transaction [Line Items]
Total revenues			98,583	90,723	297,652	252,971
OPI | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			9,363	10,640	29,448	31,722
OPI | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			89,220	80,083	268,204	221,249
SVC
Related Party Transaction [Line Items]
Total revenues			44,951	21,133	105,514	77,754
SVC | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			10,308	10,721	30,046	34,113
SVC | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			34,643	10,412	75,468	43,641
SEVN
Related Party Transaction [Line Items]
Total revenues			2,526	2,143	7,079	7,955
SEVN | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			1,333	1,137	3,563	3,392
SEVN | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			1,193	1,006	3,516	4,563
TA
Related Party Transaction [Line Items]
Total revenues			47,238	4,968	58,690	12,734
TA | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			47,238	4,441	55,214	11,499
TA | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			0	527	3,476	1,235
Private Capital
Related Party Transaction [Line Items]
Total revenues			24,091	25,620	76,991	63,887
Private Capital | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			9,425	8,960	27,042	22,152
Private Capital | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			14,666	16,660	49,949	41,735
AlerisLife
Related Party Transaction [Line Items]
Total revenues			1,381	1,338	4,111	3,855
AlerisLife | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			1,381	1,239	4,014	3,610
AlerisLife | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			0	99	97	245
Sonesta
Related Party Transaction [Line Items]
Total revenues			2,796	2,537	7,498	6,176
Sonesta | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			2,796	2,491	6,954	6,092
Sonesta | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			0	46	544	84
Other private entities
Related Party Transaction [Line Items]
Total revenues			19,914	21,745	65,382	53,856
Other private entities | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			5,248	5,230	16,074	12,450
Other private entities | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			14,666	16,515	49,308	41,406
Nonrelated Party
Related Party Transaction [Line Items]
Total revenues			52	46	52	99
Nonrelated Party | Total management and advisory services revenues
Related Party Transaction [Line Items]
Total revenues			52	46	52	99
Nonrelated Party | Total reimbursable costs
Related Party Transaction [Line Items]
Total revenues			$ 0	$ 0	$ 0	$ 0

Related Person Transactions - A

Related Person Transactions - Amount Due from Related Parties (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Related Party Transaction [Line Items]
Accounts receivable	$ 26,799	$ 21,084
Reimbursable costs	81,934	102,294
Total	108,733	123,378
Perpetual Capital
Related Party Transaction [Line Items]
Accounts receivable	22,500	19,187
Reimbursable costs	75,999	94,062
Total	98,499	113,249
Managed Equity REITs
Related Party Transaction [Line Items]
Accounts receivable	19,385	17,295
Reimbursable costs	74,566	81,165
Total	93,951	98,460
DHC
Related Party Transaction [Line Items]
Accounts receivable	4,692	8,098
Reimbursable costs	15,525	14,148
Total	20,217	22,246
ILPT
Related Party Transaction [Line Items]
Accounts receivable	3,928	3,235
Reimbursable costs	7,739	13,717
Total	11,667	16,952
OPI
Related Party Transaction [Line Items]
Accounts receivable	6,125	335
Reimbursable costs	45,206	47,943
Total	51,331	48,278
SVC
Related Party Transaction [Line Items]
Accounts receivable	4,640	5,627
Reimbursable costs	6,096	5,357
Total	10,736	10,984
SEVN
Related Party Transaction [Line Items]
Accounts receivable	3,115	1,768
Reimbursable costs	1,433	1,262
Total	4,548	3,030
TA
Related Party Transaction [Line Items]
Accounts receivable	0	124
Reimbursable costs	0	11,635
Total	0	11,759
Private Capital
Related Party Transaction [Line Items]
Accounts receivable	4,299	1,897
Reimbursable costs	5,935	8,232
Total	10,234	10,129
AlerisLife
Related Party Transaction [Line Items]
Accounts receivable	68	112
Reimbursable costs	0	492
Total	68	604
Sonesta
Related Party Transaction [Line Items]
Accounts receivable	65	127
Reimbursable costs	0	290
Total	65	417
Other private entities
Related Party Transaction [Line Items]
Accounts receivable	4,166	1,658
Reimbursable costs	5,935	7,450
Total	$ 10,101	$ 9,108

Related Person Transactions - L

Related Person Transactions - Leases (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
ABP Trust and Managed REIT
Related Party Transaction [Line Items]
Lease expense, rental expense	$ 1,221	$ 1,470	$ 4,052	$ 4,444

Related Person Transactions - T

Related Person Transactions - Tax Related Payments (Details) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
RMR LLC
Related Party Transaction [Line Items]
Tax distributions	$ 25,758	$ 11,559
ABP Trust | RMR LLC
Related Party Transaction [Line Items]
Tax distributions	$ 23,099	10,410
ABP Trust | Up C Transaction
Related Party Transaction [Line Items]
Tax receivable agreement, percent of payment	85%
Liability related to tax receivable agreement	$ 25,583
Current portion of liability related to tax receivable agreement	2,275
ABP Trust and Managed REIT | RMR LLC
Related Party Transaction [Line Items]
Tax distributions	$ 48,857	$ 21,969

Related Person Transactions - P

Related Person Transactions - Purchase of SEVN shares (Details) - USD ($) $ in Thousands		9 Months Ended
	May 11, 2022	Jun. 30, 2023	Jun. 30, 2022
Related Party Transaction [Line Items]
Purchase price		$ 0	$ 9,469
SEVN | Tremont Reality Capital
Related Party Transaction [Line Items]
Ownership percentage		11.60%
SEVN | Tremont Reality Capital | Related Party
Related Party Transaction [Line Items]
Number of shares purchased (in shares)	882,407
Purchase price	$ 9,469
Number of shares owned (in shares)		1,708,058
SEVN | Adam D. Portnoy | Related Party
Related Party Transaction [Line Items]
Ownership percentage		13.50%

Related Person Transactions -_2

Related Person Transactions - TA Merger (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	May 15, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Mar. 31, 2023
Related Party Transaction [Line Items]
Proceeds from sale of TravelCenters of America Inc. common shares				$ 53,479	$ 0
Total revenues		$ 280,225	$ 211,088	739,384	590,310
Related Party
Related Party Transaction [Line Items]
Total revenues		$ 280,173	$ 211,042	$ 739,332	$ 590,211
Termination and incentive business management fees
Related Party Transaction [Line Items]
Total revenues	$ 45,282
Termination and incentive business management fees | Related Party
Related Party Transaction [Line Items]
Total revenues	45,282
TA
Related Party Transaction [Line Items]
Proceeds from sale of TravelCenters of America Inc. common shares	53,479
TA | Related Party
Related Party Transaction [Line Items]
Proceeds from sale of TravelCenters of America Inc. common shares	$ 53,479
RMR LLC | TA
Related Party Transaction [Line Items]
Ownership percentage						4.10%
RMR LLC | TA | Related Party
Related Party Transaction [Line Items]
Ownership percentage		4.10%		4.10%
TA | BP Products North America Inc
Related Party Transaction [Line Items]
Business acquisition share price (in dollars per share)	$ 86
TA | BP Products North America Inc | Related Party
Related Party Transaction [Line Items]
Business acquisition share price (in dollars per share)	$ 86

Related Person Transactions - O

Related Person Transactions - OPI’s Merger Agreement with DHC (Details)	9 Months Ended
	Jun. 30, 2023
DHC
Related Party Transaction [Line Items]
Renovation and repositioning fee percentage	3%

Related Person Transactions - S

Related Person Transactions - Separation Arrangements (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 27, 2023	Jul. 31, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Related Party Transaction [Line Items]
Separation costs			$ 1,064	$ 400	$ 2,002	$ 617
Related Party
Related Party Transaction [Line Items]
Separation costs				400		617
SEVN | Subsequent Event
Related Party Transaction [Line Items]
Management fee percentage		3%
Retirement Agreement | Mr. Pertchik
Related Party Transaction [Line Items]
Related party transaction	$ 211
Construction Supervision Fees | SEVN | Subsequent Event
Related Party Transaction [Line Items]
Management fee percentage		5%
Former Nonexecutive Officer | Related Party
Related Party Transaction [Line Items]
Cash severance costs			708	252	1,520	469
Equity severance costs			$ 356	$ 148	$ 482	$ 148

Shareholders_ Equity - Narrativ

Shareholders’ Equity - Narrative (Details) $ / shares in Units, $ in Thousands										3 Months Ended		9 Months Ended
	Jul. 13, 2023 USD ($) $ / shares shares	May 18, 2023 USD ($)	Mar. 29, 2023 $ / shares shares	Feb. 16, 2023 USD ($)	Nov. 17, 2022 USD ($)	May 19, 2022 USD ($)	May 18, 2022 USD ($)	Feb. 17, 2022 USD ($)	Nov. 18, 2021 USD ($)	Jun. 30, 2023 USD ($) vesting_installment shares	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) vesting_installment shares	Jun. 30, 2022 USD ($)
Class of Stock [Line Items]
General and administrative										$ 9,575	$ 8,323	$ 28,198	$ 24,464
Equity based compensation expense										$ 478	$ 581	$ 1,576	1,823
Unvested shares outstanding (in shares) | shares										170,420		170,420
Vesting 2023
Class of Stock [Line Items]
Shares vesting (in shares) | shares												62,160
Vesting 2024
Class of Stock [Line Items]
Shares vesting (in shares) | shares												49,920
Vesting 2025
Class of Stock [Line Items]
Shares vesting (in shares) | shares												36,740
Vesting 2026
Class of Stock [Line Items]
Shares vesting (in shares) | shares												21,600
Class A Common Stock | 2016 Omnibus Equity Plan
Class of Stock [Line Items]
Number of annual installments | vesting_installment										5		5
Shares granted (in shares) | shares			3,000
Share price (in dollars per share) | $ / shares			$ 25.80
General and administrative												$ 464
Shares repurchased (in shares) | shares												7,383
Shares repurchased during period												$ 179
Class A and B-1 common shares
Class of Stock [Line Items]
Value of dividends		$ 6,648		$ 6,641	$ 6,642	$ 6,601		$ 6,265	$ 6,264			19,931	19,130
Class A and B-1 common shares | Subsequent Event
Class of Stock [Line Items]
Dividends declared (in usd per share) | $ / shares	$ 0.40
Value of dividends	$ 6,645
Membership Units | RMR LLC
Class of Stock [Line Items]
Value of dividends				10,113	10,114	10,080	$ 10,118	9,446	9,446			30,345	28,972
Membership Units | RMR LLC | RMR, Inc
Class of Stock [Line Items]
Value of dividends				5,313	5,314	5,280	5,318	4,946	4,946			15,945	15,172
Membership Units | RMR LLC | ABP Trust
Class of Stock [Line Items]
Value of dividends				$ 4,800	$ 4,800	$ 4,800	$ 4,800	$ 4,500	$ 4,500			$ 14,400	$ 13,800
Membership Units | Subsequent Event | RMR LLC
Class of Stock [Line Items]
Shares owned (in shares) | shares	16,613,279
Membership Units | Subsequent Event | RMR LLC
Class of Stock [Line Items]
Dividends declared (in usd per share) | $ / shares	$ 0.32
Value of dividends	$ 10,116
Membership Units | Subsequent Event | RMR LLC | RMR, Inc
Class of Stock [Line Items]
Value of dividends	5,316
Membership Units | Subsequent Event | RMR LLC | ABP Trust
Class of Stock [Line Items]
Value of dividends	$ 4,800
Membership Units | Subsequent Event | ABP Trust | RMR LLC
Class of Stock [Line Items]
Shares owned (in shares) | shares	15,000,000

Shareholders_ Equity - Distribu

Shareholders’ Equity - Distributions (Details) - USD ($) $ / shares in Units, $ in Thousands								9 Months Ended
	May 18, 2023	Feb. 16, 2023	Nov. 17, 2022	May 19, 2022	May 18, 2022	Feb. 17, 2022	Nov. 18, 2021	Jun. 30, 2023	Jun. 30, 2022
Class A and B-1 common shares
Class of Stock [Line Items]
Dividends paid (in usd per share)	$ 0.40	$ 0.40	$ 0.40	$ 0.40		$ 0.38	$ 0.38	$ 1.20	$ 1.16
Value of dividends	$ 6,648	$ 6,641	$ 6,642	$ 6,601		$ 6,265	$ 6,264	$ 19,931	$ 19,130
RMR LLC | Membership Units
Class of Stock [Line Items]
Dividends paid (in usd per share)		$ 0.32	$ 0.32	$ 0.32	$ 0.32	$ 0.30	$ 0.30	$ 0.96	$ 0.92
Value of dividends		$ 10,113	$ 10,114	$ 10,080	$ 10,118	$ 9,446	$ 9,446	$ 30,345	$ 28,972
RMR LLC | RMR, Inc | Membership Units
Class of Stock [Line Items]
Value of dividends		5,313	5,314	5,280	5,318	4,946	4,946	15,945	15,172
RMR LLC | ABP Trust | Membership Units
Class of Stock [Line Items]
Value of dividends		$ 4,800	$ 4,800	$ 4,800	$ 4,800	$ 4,500	$ 4,500	$ 14,400	$ 13,800

Per Common Share Amounts - Narr

Per Common Share Amounts - Narrative (Details) - Class A Membership Units	9 Months Ended
	Jun. 30, 2023 shares
Class of Stock [Line Items]
Antidilutive securities (in shares)	15,000,000
Conversion ratio	1

Per Common Share Amounts - Earn

Per Common Share Amounts - Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Numerators:
Net income attributable to The RMR Group Inc.	$ 24,641	$ 7,570	$ 49,451	$ 22,004
Less: income attributable to unvested participating securities	(273)	(72)	(580)	(213)
Net income attributable to The RMR Group Inc. used in calculating basic EPS	24,368	7,498	48,871	21,791
Add back: income attributable to unvested participating securities	0	72	580	213
Add back: net income attributable to noncontrolling interest	0	9,695	61,262	28,142
Add back: income tax expense	0	2,943	18,581	8,448
Less: income tax expense assuming redemption of noncontrolling interest’s Class A units for Class A common shares	0	(5,851)	(35,932)	(16,833)
Net income used in calculating diluted EPS	$ 24,368	$ 14,357	$ 93,362	$ 41,761
Denominators:
Common shares outstanding (in shares)	16,614	16,501	16,614	16,501
Less: unvested participating securities and incremental impact of weighted average (in shares)	(179)	(158)	(198)	(169)
Weighted average common shares outstanding - basic (in shares)	16,435	16,343	16,416	16,332
Add: assumed redemption of noncontrolling interest’s Class A Units for Class A common shares (in shares)	0	15,000	15,000	15,000
Add: Incremental unvested shares (in shares)	0	10	15	10
Weighted average common shares outstanding - diluted (in shares)	16,435	31,353	31,431	31,342
Net income attributable to The RMR Group Inc. per common share - basic (in dollars per share)	$ 1.48	$ 0.46	$ 2.98	$ 1.33
Net income attributable to The RMR Group Inc. per common share - diluted (in dollars per share)	$ 1.48	$ 0.46	$ 2.97	$ 1.33
Effective tax rate		29%	27.80%	28.70%

Net Income Attributable to RM_3

Net Income Attributable to RMR Inc. (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Net Income Attributable to RMR Inc.
Income before income tax expense	$ 64,385	$ 20,208	$ 129,294	$ 58,594
RMR Inc. franchise tax expense and interest income	(110)	149	(255)	485
Net income before noncontrolling interest	64,275	20,357	129,039	59,079
Net income attributable to noncontrolling interest	(30,530)	(9,695)	(61,262)	(28,142)
Net income attributable to RMR Inc. before income tax expense	33,745	10,662	67,777	30,937
Income tax expense attributable to RMR Inc.	(9,214)	(2,943)	(18,581)	(8,448)
RMR Inc. franchise tax expense and interest income	110	(149)	255	(485)
Net income attributable to The RMR Group Inc.	$ 24,641	$ 7,570	$ 49,451	$ 22,004

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event - MPC Partnership Holdings LLC $ in Thousands	Jul. 29, 2023 USD ($)
Subsequent Event [Line Items]
Payments to acquire businesses, gross	$ 80,000
Contingent consideration	$ 20,000
Baseline percentage of revenue	85%