Supplemental Detail for Certain Components of Consolidated Balance Sheets (Details 4) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Accounts payable and accrued expenses
Accrued costs on properties under development	$ 11,556	$ 8,595
Other items	26,859	21,122
Total accounts payable and accrued expenses	69,299	70,426
Acquired lease intangible liabilities, net
Acquired below-market leases	145,638	28,975
Accumulated amortization of acquired below-market leases	(7,945)	(2,504)
Acquired lease intangible liabilities	137,693	26,471
Other liabilities
Rent received in advance	26,007	20,929
Preferred units issued upon acquisition of ARCT	6,750
Security deposits	6,035	5,130
Total other liabilities	38,792	26,059
Note
Accounts payable and accrued expenses
Interest payable	27,877	40,061
Mortgages
Accounts payable and accrued expenses
Interest payable	$ 3,007	$ 648