Noncontrolling Interests (Property Partnerships) (Narrative) (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Noncontrolling Interest [Line Items]
Property partnerships	$ (1,852)	$ (1,063)

Carrying amount of the equity interests owned by noncontrolling partners of a limited partnership included in the entity's consolidated financial statements.

No definition available.

Name:	us-gaap_MinorityInterestInLimitedPartnerships
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant