Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 Property
Contingencies And Commitments [Line Items]
Number of existing retail properties	10
Minimum amount of compensatory and consequential damages	Not less than $500 million
Aggregate amount related to construction of shopping centers	$ 34.9
Outstanding letters of credit	44.4
Capital associated with Amount outstanding to the development of projects	7.6
Priority return on capital advances	8.50%
Affiliate debt guarantee	15.4
Annual base rental income for various affiliates	$ 2.2
Long-term ground leases expiration period	2070
Minimum period space in shopping centers leased	1 month
Maximum period space in shopping centers leased	30 years
Minimum [Member]
Contingencies And Commitments [Line Items]
Construction contracts due	12 months
Maximum [Member]
Contingencies And Commitments [Line Items]
Construction contracts due	36 months