Real Estate Properties (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended				3 Months Ended
	Mar. 31, 2014 property	Mar. 31, 2013	Mar. 31, 2014 MOBs building property	Dec. 31, 2013 MOBs property building	Mar. 31, 2014 Discontinued operations, properties sold or held for sale MOBs building property	Mar. 31, 2013 Discontinued operations, properties sold or held for sale MOBs
Real estate properties
Number of properties that met the criteria for discontinued operations	13		4	4	4
Number of buildings that met the criteria for discontinued operations			7	7	7
Rental income	$ 112,055	$ 111,852			$ 2,294	$ 2,521
Property operating expenses	(77,802)	(73,679)			(994)	(903)
Depreciation and amortization	(38,355)	(37,703)				(599)
Income from discontinued operations	$ 1,300	$ 1,019			$ 1,300	$ 1,019