Segment Disclosures (Details 3) (USD $)	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2011 Identifiable segment	Dec. 31, 2010 Identifiable segment	Sep. 30, 2011 Senior housing	Dec. 31, 2010 Senior housing	Sep. 30, 2011 Post-acute/skilled	Dec. 31, 2010 Post-acute/skilled	Sep. 30, 2011 Life science	Dec. 31, 2010 Life science	Sep. 30, 2011 Medical office	Dec. 31, 2010 Medical office	Sep. 30, 2011 Hospital	Dec. 31, 2010 Hospital	Sep. 30, 2011 Other non-segment	Dec. 31, 2010 Other non-segment	Oct. 05, 2006 CRC
Reconciliation of assets from segment to consolidated
Gross segment assets			$ 18,551,103,000	$ 13,282,407,000	$ 5,969,625,000	$ 4,364,026,000	$ 5,612,116,000	$ 2,133,640,000	$ 3,875,744,000	$ 3,709,528,000	$ 2,336,474,000	$ 2,305,175,000	$ 757,144,000	$ 770,038,000
Accumulated depreciation and amortization			(1,650,685,000)	(1,434,150,000)
Total assets	17,439,377,000	13,331,923,000	16,900,418,000	11,848,257,000											538,959,000	1,483,666,000
Amount paid in merger in excess of the fair value, recorded as goodwill																	51,700,000
Goodwill	$ 50,346,000	$ 50,346,000			$ 30,500,000		$ 3,300,000				$ 11,400,000		$ 5,100,000