Mortgages on Operating Properties (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended	3 Months Ended
	May 10, 2013	Mar. 31, 2013	Dec. 31, 2012
Mortgages on Operating Properties [Abstract]
Retirement of debt, number of instruments		2
Debt maturing in current year with extension available		$ 26,200
Debt Maturing In Current Year Without Extension Options Available		99,006
Extinguishment of Debt, Amount	299,740	77,099
Weighted average maturity of mortgage and other indebtedness (in years)		4.74	4.9
Schedule of principal repayments [Abstract]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months		417,904
2013		220,984
2014		879,696
2015		927,500
2016		552,682
Thereafter		1,669,379
Total payments		4,668,145
Net unamortized premiums		12,376
Mortgage and other indebtedness		4,680,521	4,745,683
Statesboro Crossing [Member]
Mortgages on Operating Properties [Abstract]
Extinguishment of Debt, Amount		13,460
Columbia Place [Member]
Mortgages on Operating Properties [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages		27,265
Debt Instrument, Maturity Date		Sep. 01, 2013
Westmoreland Mall [Member]
Mortgages on Operating Properties [Abstract]
Extinguishment of Debt, Amount		63,639
Property Loans Maturing [Member]
Schedule of principal repayments [Abstract]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months		125,206
Term Loans Maturing [Member]
Mortgages on Operating Properties [Abstract]
Extinguishment of Debt, Amount	228,000
Principal Amortization [Member]
Schedule of principal repayments [Abstract]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months		$ 64,698