Financing Activity - Mortgage Loan Activity (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended
	Feb. 28, 2013 Lycoming Mall [Member]	Mar. 31, 2010 Lycoming Mall [Member]	Oct. 31, 2009 Lycoming Mall [Member]	Sep. 09, 2008 Logan Valley Mall [Member]
Mortgage Loan Activity [Line Items]
Mortgage Loans On Real Estate Initial Amount Drawn	$ 28.0			$ 68.0
Additional Loan Amount Drawn	2.1	2.5	5.0
Unamortized balance of mortgage loan	33.4
Total mortgage amount	$ 35.5