Organization and Business (Details) (USD $)	Dec. 31, 2013 property	Dec. 31, 2012	Dec. 31, 2013 Senior Living Communities property unit state	Dec. 31, 2013 Independent and assisted living communities unit property	Dec. 31, 2013 SNF unit property	Dec. 31, 2013 Independent living apartment unit	Dec. 31, 2013 Assisted living suites unit	Dec. 31, 2013 Skilled nursing units unit	Dec. 31, 2013 Assisted living communities property	Dec. 31, 2013 Assisted living communities unit	Dec. 31, 2013 SNH property	Dec. 31, 2001 SNH	Dec. 31, 2013 SNH Senior Living Communities property	May 31, 2011 SNH Senior Living Communities property	Dec. 31, 2013 SNH SNF unit	Dec. 31, 2013 SNH Assisted living communities property unit
Real estate properties
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01										$ 0.01
Number of properties operated			255	224	31									6
Number of states in which real estate properties are located			31
Number of living units in properties operated			30,023	27,201	2,822	10,368	14,399	5,256
Number of living units in properties excluded due to temporary closing for renovations			48
Number of properties from which 48 living units were excluded			1
Number of properties owned and operated			30
Number of living units in properties owned and operated			2,946
Number of properties leased and operated	191		181										187
Number of units in properties leased and operated			20,026
Number of properties managed			44										44
Number of units in properties managed			7,051
Number of real estate properties classified as discontinued operations									1	32	4		10			4
Number of units in real estate property classified as discontinued operations															6	712