Subsequent Events - Additional Information (Detail) (USD $)	3 Months Ended			3 Months Ended				1 Months Ended	3 Months Ended		1 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Mar. 31, 2013 Westwood Village		Dec. 31, 2012 Westwood Village		Apr. 30, 2013 Five Forks Place	Mar. 31, 2013 Five Forks Place	Dec. 31, 2012 Five Forks Place	Apr. 30, 2013 Amendment to Loan Agreement Westwood Village	Apr. 30, 2013 Amendment to Loan Agreement Westwood Village Refinancing of Debt	Apr. 30, 2013 Disposition Of Real Properties Retail Properties	Apr. 30, 2013 Other Prepayment Five Forks Place
Subsequent Event [Line Items]
Maturity date	Jul. 19, 2016			May 01, 2020							Jun. 01, 2013	May 01, 2020
Payment of mortgage notes	$ 1,234,000	$ 1,066,000									$ 10,000,000			$ 20,000,000
Carrying Amount of Mortgage Notes	332,160,000		333,310,000	50,000,000	[1]	50,000,000	[1]		4,833,000	4,882,000	40,000,000	39,700,000
Contractual Interest Rate				2.69%	[1]				5.50%			3.30%
Proceed from sale of Pavilions Crossing property													$ 16,300,000
Maturity Date				2013	[1]			2013	2013

[1] The loan at the West Broad Village property was refinanced and the maturity date extended subsequent to May 1, 2020; see Note 18 for further discussion.