Impairment Charges and Impairment of Joint Venture Investments - Impairment Charges on Assets or Investments (Parenthetical) (Detail) - ShoppingCenter	Dec. 31, 2016	Dec. 31, 2015
Operating Shopping Centers [Member]
Schedule Of Investments [Line Items]
Number of properties	20	25

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_ScheduleOfInvestmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration