CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 20,448	$ 35,624
Other comprehensive income (loss), net of tax:
Unrealized gain on derivative instruments	1,000	1,051
Foreign currency translation adjustments	10,587	973
Equity in unrealized income (loss) of an investee	20	(16)
Total comprehensive income	32,055	37,632
Less: comprehensive income attributable to noncontrolling interest in consolidated subsidiary		(9,953)
Comprehensive income attributable to CommonWealth REIT	$ 32,055	$ 27,679