CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME
Net (loss) income	$ (216,207)	$ 22,265	$ (151,666)	$ 67,425
Other comprehensive (loss) income, net of tax:
Unrealized gain (loss) on derivative instruments	178	454	4,011	(1,987)
Foreign currency translation adjustments	5,455	4,516	(31,393)	5,597
Equity in unrealized income (loss) of an investee	13	69	(149)	65
Total comprehensive (loss) income	(210,561)	27,304	(179,197)	71,100
Less: comprehensive income attributable to noncontrolling interest in consolidated subsidiary	(108)	(4,657)	(20,057)	(10,072)
Comprehensive (loss) income attributable to CommonWealth REIT	$ (210,669)	$ 22,647	$ (199,254)	$ 61,028