Revenue Recognition (Details) - USD ($)		3 Months Ended			9 Months Ended
	Jun. 05, 2015	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Business Management and Incentive Fees
Incentive fee allocated to related party					$ (26,611,000)
Property Management Fees
Preperty management fee percent based on gross collected rents					3.00%
Property management fee percent based on the cost of construction					$ 5.0
Aggregate property management fees		$ 8,440,000		$ 7,731,000	24,870,000	$ 21,400,000
Reimbursable Payroll and Related Costs
Equity based compensation expense and related reimbursements		2,128,000		953,000	4,971,000	4,435,000
Reimbursable payroll and related costs		9,744,000		6,427,000	25,993,000	20,535,000
Advisory Fees
Investment Advisory Fees		600,000		596,000	$ 1,741,000	1,801,000
Managed REIT's
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%
Business management fees as a percentage of average invested capital above the threshold limit					0.50%
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%
Maximum threshold amount for calculating the business management fees		250,000			$ 250,000
Minimum threshold amount for calculating the business management fees		250,000			$ 250,000
Termination fee remaining term assumption					10 years
Percentage of business management fees paid in the form of cash	90.00%
Percentage of business management fees paid in the form of common shares	10.00%
Contingent incentive business management fee percentage					12.00%
Measurement period for calculating the annual incentive fee as of December 31, 2015			2 years
Measurement period for calculating the annual incentive fee after December 31, 2015					3 years
Aggregate base business management fees		26,623,000		27,070,000	$ 76,628,000	76,763,000
Aggregate incentive business management fees					$ 62,263,000	0
AIC
Business Management and Incentive Fees
Business management fee percent based on total premiums paid					3.00%
Managed Operators, ABP Trust and AIC
Business Management and Incentive Fees
Business management fee percent based on management agreements					0.60%
Aggregate business management fees		6,804,000		6,181,000	$ 19,121,000	18,229,000
RIF
Advisory Fees
Advisory fee percent					0.85%
Up C Transaction | ABP Trust
Business Management and Incentive Fees
Incentive fee allocated to related party			$ 26,611,000		$ 26,611,000
RMR LLC | Up C Transaction
Business Management and Incentive Fees
Number of business days notice for termination of property management agreement for convenience by the related party	60 days
Number of business days notice for termination of property management agreement for performance by the related party	60 days
Window for providing notice of termination of property management agreement for performance by the related party	60 days
Window for providing notice of termination of property management agreement for change of control by the related party	12 months
RMR LLC | EQC Termination and Cooperation Agreement | EQC
Property Management Fees
Amount Paid For Transition Service				174,000		$ 6,097,000
Aggregate property management fees		$ 0		$ 174,000	$ 58,000