Real Property Acquisitions and Development (Details Textuals) (USD $)	12 Months Ended
	Dec. 31, 2013 properties		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Sunrise [Member]	Dec. 31, 2012 Sunrise [Member]	Dec. 31, 2011 Sunrise [Member]	Jul. 02, 2013 Sunrise [Member] properties	Aug. 01, 2012 Sunrise [Member]	Dec. 31, 2013 Sunrise [Member] Controlling [Member] properties	Dec. 31, 2013 Sunrise [Member] Non Controlling [Member] properties	May 28, 2013 Revera [Member] properties	May 28, 2013 Revera [Member] Controlling [Member]	May 28, 2013 Revera [Member] Non Controlling [Member]
Real Property Acquisitions And Developmen Textuals [Line Items]
Cash disbursed for acquisitions					$ 2,456,011,000
Properties	1,142	[1]						49		120	5	47
Percentage of partnership owned	20.00%												75.00%	25.00%
Purchase price per share									$ 14.5
Total purchase price	91,000,000				4,155,052,000							1,318,168,000
Total revenues	2,880,608,000		1,805,044,000	1,313,182,000	654,717,000	22,930,000	0
Net Operating Income	1,673,795,000		1,237,055,000	938,118,000	216,827,000	11,698,000	0
Transaction costs	$ 133,401,000		$ 61,609,000	$ 70,224,000	$ 77,187,000

[1] Genesis is in our seniors housing triple-net segment. Sunrise, Revera, and Belmont Village are in our seniors housing operating segment. Benchmark is in both our seniors housing triple-net and seniors housing operating segments