Loan Receivable (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended		1 Months Ended		3 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Five Star	Sep. 30, 2011 Five Star	May 31, 2011 Five Star	Jun. 30, 2011 Five Star Senior living communities	May 31, 2011 Five Star Senior living communities property	Sep. 30, 2011 Five Star Senior living communities property	Sep. 30, 2011 Senior living communities property
Loans Receivable
Amount agreed to be lent under Bridge Loan Agreement							$ 80,000
Number of properties funded under Bridge Loan									6
Aggregate purchase price of properties acquired by borrower									122,800
Amount borrowed under the Bridge Loan								80,000		39,000
Amount repaid by borrower								32,000
Aggregate principal amount outstanding under Bridge Loan										48,000
Number of properties mortgaged										3	4
Spread over annual rates of interest applicable to borrowings under revolving credit facility (as a percent)					1.00%	1.00%
Interest rate under the bridge loan (as a percent)					2.80%	2.80%
Interest income recognized	$ 462	$ 203	$ 971	$ 703	$ 187	$ 245