Financing Activity - Mortgage Loan Activity (Detail) (USD $)	9 Months Ended		1 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Jul. 31, 2014 The Gallery at Market East [Member]	Jul. 31, 2014 Logan Valley Mall [Member]
Mortgage Loan Activity [Line Items]
Repayments of Secured Debt	$ 76,784,000	$ 294,514,000	$ 25,800,000	$ 51,000,000
Available Cash From Working Capital Used to Repay Mortgage Debt				$ 1,000,000