Investments in Unconsolidated Entities (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]
Income (loss) from unconsolidated entities	$ (11,516,000)	$ (5,461,000)	$ (17,073,000)	$ (3,198,000)
Equity Investments	680,558,000		680,558,000		479,629,000
Chartwell [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties in portfolio	42		42
Unamortized basis difference	8,808,000		8,808,000
Chartwell [Member] | Controlling [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties in portfolio	3		3
Chartwell [Member] | Non Controlling [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties in portfolio	39		39
Percentage of partnership owned	50.00%		50.00%
Forest City [Member] | Non Controlling [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties in portfolio	7		7
Percentage of partnership owned	49.00%		49.00%
Sunrise [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties in portfolio	54		54
Sunrise [Member] | Controlling [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties in portfolio	49		49
Sunrise [Member] | Non Controlling [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties in portfolio	5		5
Percentage of partnership owned	20.00%		20.00%
Additional ownership acquired			4%
Senior Resource Group [Member]
Schedule of Equity Method Investments [Line Items]
Equity Investments	214,832,000		214,832,000
Unamortized basis difference	$ 173,563,000		$ 173,563,000
Senior Resource Group [Member] | Non Controlling [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties in portfolio	10		10
Percentage of partnership owned	46.79%		46.79%