Amount of premium paid for combined directors' and officers' liability insurance policy.

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Aggregate additional coverage amount of combined directors' and officers' liability insurance policy, purchased by the related party.

+ References

No definition available.

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Aggregate coverage amount of combined directors' and officers' liability insurance policy, purchased by the related party.

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No definition available.

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Non-indemnifiable coverage amount of combined directors' and officers' liability insurance policy, purchased by the related party.

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No definition available.

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- Definition

Represents the term of the combined property insurance policy purchased from a related party.

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No definition available.

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- Definition

Represents the term of the combined property other insurance policy purchased from a related party.

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No definition available.

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- Definition

This element represents the amount of annual premiums for property insurance pursuant to an insurance program arranged by the equity method investee.

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No definition available.

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Represents the number of entities to whom related party provides management services.

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No definition available.

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- Definition

Represents the number of independent trustees of the entity who also serve as independent trustees of the related party

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No definition available.

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- Definition

Represents the number of other equity method investees owning outstanding shares.

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No definition available.

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- Definition

Represents the number of shares purchased related to the amended restated shareholder agreement.

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No definition available.

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Represents the period of standstill provision pursuant to which the counterparty agreed not to make unsolicited proposals to acquire entities as specified.

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No definition available.

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Represents the amount of accrued dividends as defined in the stock purchase agreement.

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No definition available.

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Represents the cash purchase price paid to acquire common shares of beneficial interest of related party pursuant to the stock purchase agreement.

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No definition available.

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Represents the cash purchase price including accrued dividends paid to acquire common shares of beneficial interest of related party pursuant to the stock purchase agreement.

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No definition available.

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Represents the number of common shares of beneficial interest of related party acquired pursuant to stock purchase agreement.

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No definition available.

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Represents the per share cash purchase price excluding accrued dividends paid to acquire common shares of beneficial interest of related party pursuant to the stock purchase agreement.

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No definition available.

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Represents the per share amount of accrued dividends as defined in the stock purchase agreement.

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Represents the insurance coverage of the property insurance purchased from related parties.

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- Definition

Represents the number of shares of related party purchased. Such related party was formerly owned by former parent company of the entity.

+ References

No definition available.

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Represents the value of shares of related party purchased. Such related party was formerly owned by former parent company of the entity.

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No definition available.

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- Definition

Represents the threshold over which an affiliate can no longer be considered an "interested stockholder" under the Maryland Business Combination Act.

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No definition available.

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- Definition

This element represents the aggregate cost of investments accounted for under the equity method of accounting.

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-Name Accounting Standards Codification
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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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-Name Accounting Standards Codification
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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

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Repayment received or receivable for expenses incurred on behalf of a client or customer, other than those reimbursements received by landlords from tenants.

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

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Number of new stock issued during the period.

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Related Party Transactions - REITs, for which RMR LLC provides Management Services (Details) $ / shares in Units, $ in Thousands							1 Months Ended	6 Months Ended	12 Months Ended
	Mar. 05, 2015 shares	Mar. 04, 2015 USD ($) shares	Jul. 09, 2014 USD ($) $ / shares shares	May. 09, 2014 USD ($) shareholder shares	Mar. 15, 2013 shares	Mar. 11, 2013 USD ($)	Jun. 30, 2015	Dec. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) trustee company shares	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Aug. 31, 2015 USD ($)
Related Party Transaction
Investment at carrying value								$ 680,137	$ 491,369	$ 680,137
Recognized income (loss) related to investment									$ 18,640	10,963	$ 334
EQC
Related Party Transaction
Number of common shares sold in public offering \| shares					9,950,000
Common shares registration and sale expenses paid by related party						$ 310
Percentage of ownership interest									100.00%
RMR LLC
Related Party Transaction
Period of standstill provision pursuant to which the counterparty agreed not to make unsolicited proposals to acquire entities as specified									36 months
SIR
Related Party Transaction
Percentage of ownership interest									27.90%
Investment at carrying value								680,137	$ 491,369	680,137
Recognized income (loss) related to investment								17,113	$ 21,882
SIR \| EQC
Related Party Transaction
Cash purchase price			$ 677,500
Cash purchase price excluding accrued dividends (in dollars per share) \| $ / shares			$ 31.51
Accrued dividends			$ 11,300
Accrued dividends (in dollars per share) \| $ / shares			$ 0.53
Cash purchase price including accrued dividends			$ 688,800
RMR LLC
Related Party Transaction
Number of independent trustees of the entity who also serve as independent trustees of the related party \| trustee									1
Aggregate coverage of combined directors' and officers' liability insurance policy purchased by the related party												$ 10,000
Aggregate additional coverage of combined directors' and officers' liability insurance policy purchased by the related party												20,000
Non-indemnifiable coverage of combined directors' and officers' liability insurance policy purchased by the related party												$ 5,000
Premium paid for combined directors' and officers' liability insurance policy									$ 316	529	333
RMR LLC \| SIR \| RMR LLC \| EQC
Related Party Transaction
SIR Common shares of beneficial interest acquired pursuant to stock purchase agreement \| shares			500,000
SIR
Related Party Transaction
SIR Common shares of beneficial interest acquired pursuant to stock purchase agreement \| shares									24,918,421
Percentage of ownership interest									27.90%
Threshold exempting affiliates from interested stockholders									10.00%
SIR \| EQC
Related Party Transaction
SIR Common shares of beneficial interest acquired pursuant to stock purchase agreement \| shares			21,500,000
SIR \| Lakewood Capital Partners LP
Related Party Transaction
Cash purchase price		$ 95,203
Percentage of ownership interest		3.90%
Period of standstill provision pursuant to which the counterparty agreed not to make unsolicited proposals to acquire entities as specified									50 years
Number of shares purchased under shareholder agreement \| shares		3,418,421
SIR \| Barry Portnoy \| Lakewood Capital Partners LP
Related Party Transaction
Number of shares purchased under shareholder agreement \| shares	2,429	107,606
SIR \| Adam Portnoy \| Lakewood Capital Partners LP
Related Party Transaction
Number of shares purchased under shareholder agreement \| shares	2,429	87,606
SNH
Related Party Transaction
Number of independent trustees of the entity who also serve as independent trustees of the related party \| trustee									2
AIC
Related Party Transaction
Percentage of ownership interest				14.30%					20.00%
Number of entities to whom RMR provides management services \| company									4
Value of shares of related party purchased, formerly owned by former parent company				$ 825
Number of other companies owning outstanding shares \| shareholder				6
Amount invested in equity investee									$ 6,019
Coverage of purchased property insurance									500,000
Combined property insurance policy term							3 years
Combined property other insurance policy term							1 year
Annual premium for property insurance									1,277	526	1,161
Investment at carrying value								$ 6,946	6,946	6,946	6,031
Recognized income (loss) related to investment									$ 20	$ 87	$ 334
AIC \| EQC
Related Party Transaction
Shares of related party purchased, formerly owned by former parent company \| shares				2,857