Number of Tranches

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- Definition

Represents the number of trustees serving in the board of trustees of the reporting entity.

+ References

No definition available.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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-Publisher FASB

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-SubTopic 10

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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-Publisher FASB

-Name Accounting Standards Codification

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iv)(3)

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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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-Paragraph 2

-Subparagraph (c)(2)(iii)(3)

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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- Definition

Agreed-upon price for the exchange of the underlying asset relating to the share-based payment award.

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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- Definition

Percentage of vesting of share-based compensation awards.

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- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Staff Accounting Bulletin (SAB)

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-Section D

-Subsection 2

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- Definition

Number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP), net of any shares forfeited. Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

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-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

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- Definition

Gross value of stock (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP). Stock issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

+ References

No definition available.

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Share-Based Compensation - Narrative (Details) $ / shares in Units, $ in Millions				3 Months Ended	9 Months Ended
	Jun. 16, 2015 USD ($) trustee $ / shares shares	Jan. 28, 2015 tranche $ / shares shares	Mar. 25, 2014 shares	Sep. 30, 2015 USD ($) shares	Sep. 30, 2015 USD ($) $ / shares shares	Sep. 30, 2014 USD ($)	Jul. 31, 2014 trustee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of independent trustees \| trustee	11						11
Officers and Employees \| Employee Stock \| RMR
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense \| $						$ 3.4
Officers and Employees \| Employee Stock \| Common Stock \| RMR
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares issued (in shares)			130,914
Restricted shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of independent trustees \| trustee	9
Share based compensation amount \| $	$ 0.1
Number of equity awards granted (in shares)	34,587	126,319
Price per share (in dollars per share) \| $ / shares	$ 26.02
Vesting period	1 year	4 years
Number of shares forfeited (in shares)					8,115
Weighted average share price for forfeited shares (in dollars per share) \| $ / shares					$ 26.64
Granted shares value (in dollars per share) \| $ / shares		$ 26.58
Estimated future compensation expense for unvested shares \| $				$ 16.0	$ 16.0
Weighted average period over which compensation expense will be recorded					3 years
Restricted shares \| Independent Trustee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity awards granted (in shares)	3,843
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term of incentive plan after effective date					4 years
Number of equity awards granted (in shares)		256,467
Number of shares forfeited (in shares)					16,475
Weighted average share price for forfeited shares (in dollars per share) \| $ / shares					$ 20.50
Granted shares value (in dollars per share) \| $ / shares					$ 38.55
Estimated future compensation expense for unvested shares \| $				$ 22.5	$ 22.5
Weighted average period over which compensation expense will be recorded					2 years 8 months 12 days
Number of tranches \| tranche		2
Restricted stock units \| Vesting on January 28, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent		50.00%
Restricted stock units \| Vesting on January 28, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percent		50.00%
2015 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term of incentive plan after effective date	10 years
2015 Incentive Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares available for issuance (in shares)	3,250,000
Share award plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares available for issuance (in shares)				3,215,413	3,215,413
Share award plan \| General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense \| $				$ 3.7	$ 11.8