Investments in Partnerships (Narrative) (Detail)	12 Months Ended
	Dec. 31, 2013 Property
Mortgage Loans on Real Estate [Line Items]
Mortgage loan secured by number of properties	8
Number of fixed rate mortgage loans payable	5
Number of variable rate mortgage loans payable	3
Leigh Valley Associates, LP
Mortgage Loans on Real Estate [Line Items]
Partnership investment, ownership interest	50.00%
Mortgage Loan [Member]
Mortgage Loans on Real Estate [Line Items]
Property under development	1
Mortgage loan due date	2023
Weighted average interest rate of all partnership mortgage loans	5.08%
Fixed Interest Rate [Member] | Mortgage Loan [Member]
Mortgage Loans on Real Estate [Line Items]
Interest rate, minimum	5.00%
Interest rate, maximum	7.00%
Weighted average interest rate on mortgage loan	5.56%
Variable Interest Rate [Member] | Mortgage Loan [Member]
Mortgage Loans on Real Estate [Line Items]
Interest rate, minimum	2.93%
Interest rate, maximum	3.27%
Weighted average interest rate on mortgage loan	3.20%