Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Sep. 24, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Common Share Issuances
Common shares issued as partial payment to acquire		43,285,000
Net proceeds from sale of common shares				$ 655,211
Officers and employees of RMR
Common Share Issuances
Closing share price of the entity's common shares (in dollars per share)	$ 25.62
Shares purchased from certain of our officers and other employees of RMR LLC	16,340
RMR Inc | Common shares
Common Share Issuances
Common shares issued as partial payment to acquire		1,490,000
RMR LLC
Common Share Issuances
Common shares issued for services rendered by RMR		52,366	119,664
RMR LLC | Common shares
Common Share Issuances
Common shares issued for services rendered by RMR		63,119