Mortgage Notes Payable (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Mortgage Notes Payable [Line Items]
Mortgage notes payable weighted average remaining term ( in years)	six
Prepayment penalties	$ 13	$ 190	$ 5,610
Write off of deferred finance cost	72	340	285
Discontinued Operations [Member]
Mortgage Notes Payable [Line Items]
Prepayment penalties			4,717
Write off of deferred finance cost		$ 216	$ 210
Fixed Rate Mortgage Notes Payable [Member]
Mortgage Notes Payable [Line Items]
Weighted average interest rate	5.34%	5.36%
Variable Rate Mortgage Notes Payable [Member]
Mortgage Notes Payable [Line Items]
Weighted average interest rate	2.98%	3.00%