Investments in Unconsolidated Entities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended			6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Jun. 30, 2013 Senior housing - triple net [Member] properties		Jun. 30, 2012 Senior housing - triple net [Member]		Jun. 30, 2013 Senior housing - operating [Member] properties	Jun. 30, 2012 Senior housing - operating [Member]	Jun. 30, 2013 Medical facilities [Member] properties	Jun. 30, 2012 Medical facilities [Member]	Dec. 31, 2010 Strategic Medical Office Partnership [Member] properties	Dec. 31, 2010 Strategic Medical Office Partnership [Member] Controlling [Member] properties	Dec. 31, 2010 Strategic Medical Office Partnership [Member] Non Controlling [Member] properties	Jun. 30, 2013 Chartwell [Member]	Jun. 30, 2012 Chartwell [Member] properties	Jun. 30, 2012 Chartwell [Member] Controlling [Member] properties	Jun. 30, 2013 Chartwell [Member] Non Controlling [Member] properties	Jun. 30, 2012 Chartwell [Member] Non Controlling [Member] properties	Dec. 31, 2010 Forest City [Member] properties	Jun. 30, 2013 Sunrise [Member]	Jun. 30, 2013 Sunrise [Member] Non Controlling [Member] properties	Jun. 30, 2013 Management Buyer [Member]
Schedule of Equity Method Investments [Line Items]
Income from unconsolidated entities	$ (5,461)	$ 1,456	$ (3,198)	$ 2,989		$ 2,481	[1]	$ (2)	[1]	$ (9,556)	$ (928)	$ 3,877	$ 3,919
Equity Investments	768,737	438,936	768,737	438,936	438,936	31,383	[1]	34,618	[1]	552,389	217,701	184,965	186,617										359,575
Investment Percentage Range						10% to 49%	[1]			33% to 50%		36% to 49%
Number of properties in portfolio						0	[1]			93		13		17	11	6		42	3	39	39	7		54
Percentage of partnership owned																		50.00%				49.00%			20.00%
Unamortized investment																	$ 9,394

[1] (1) Asset amounts include an available-for-sale equity investment. See Note 16 for additional information.