Related Parties (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
General And Administrative Expenses [Member]
Related Party Transaction [Line Items]
Reimbursements from general and administrative expenses	$ 285,000	$ 222,000	$ 409,000	$ 554,000
Gazit Globe Ltd [Member]
Related Party Transaction [Line Items]
Related party rental income	83,000	79,000	255,000	232,000
Due from Gazit	245,000		245,000		126,000
MGN Icarus, Inc [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ 44,000	$ 85,000	$ 194,000	$ 137,000