Capital Expenditures for Each Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Segment Reporting Information [Line Items]
Capital Expenditures	$ 10,240	[1]	$ 6,457	[1]
Total Retail
Segment Reporting Information [Line Items]
Capital Expenditures	1,947	[1]	3,430	[1]
Total Office
Segment Reporting Information [Line Items]
Capital Expenditures	7,862	[1]	2,712	[1]
Total Multifamily
Segment Reporting Information [Line Items]
Capital Expenditures	143	[1]	238	[1]
Total Mixed-Use
Segment Reporting Information [Line Items]
Capital Expenditures	$ 288	[1]	$ 77	[1]

[1] Capital expenditures represent cash paid for capital expenditures during the period and include leasing commissions paid.