CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Common Shares	Additional Paid In Capital	Cumulative Net Income	Cumulative Other Comprehensive Income (Loss)	Cumulative Common Distributions	Total
Balance at Dec. 31, 2012	$ 547	$ 1,103,982	$ 137,293	$ 99	$ (214,470)	$ 1,027,451
Balance (in shares) at Dec. 31, 2012	54,643,888
Increase (Decrease) in Shareholders' Equity
Share grants		1,697				1,697
Share grants (in shares)	78,130
Unrealized loss from investees				(50)		(50)
Net income (loss)			54,620			54,620
Distribution paid to common shareholders					(94,043)	(94,043)
Balance at Dec. 31, 2013	$ 547	1,105,679	191,913	49	(308,513)	989,675
Balance (in shares) at Dec. 31, 2013	54,722,018
Increase (Decrease) in Shareholders' Equity
Issuance of shares, net	$ 155	350,558				350,713
Issuance of shares, net (in shares)	15,563,559
Share grants	$ 1	1,394				1,395
Share grants (in shares)	63,650
Unrealized loss from investees				(12)		(12)
Net income (loss)			56,534			56,534
Distribution paid to common shareholders					(100,856)	(100,856)
Balance at Dec. 31, 2014	$ 703	1,457,631	248,447	37	(409,369)	1,297,449
Balance (in shares) at Dec. 31, 2014	70,349,227
Increase (Decrease) in Shareholders' Equity
Issuance of shares, net	$ 7	14,039				14,046
Issuance of shares, net (in shares)	723,222
Share grants	$ 1	984				985
Share grants (in shares)	65,600
Share repurchases		(172)				(172)
Share repurchases (in shares)	(11,741)
Unrealized loss from investees				(5,513)		(5,513)
Unrealized loss on investment in The RMR Group Inc.				(9,391)		(9,391)
Net income (loss)			(209,961)			(209,961)
Distribution paid to common shareholders					(121,660)	(121,660)
Distribution to the RMR Group Inc. common stock					(9,132)	(9,132)
Balance at Dec. 31, 2015	$ 711	$ 1,472,482	$ 38,486	$ (14,867)	$ (540,161)	$ 956,651
Balance (in shares) at Dec. 31, 2015	71,126,308