Fair Value - Carrying Value of Assets (Detail) (Real Estate [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Non-Financial Assets and Liabilities:
Real estate	$ 0	$ 24,161
Fair Value, Inputs, Level 1 [Member]
Non-Financial Assets and Liabilities:
Real estate	0	0
Fair Value, Inputs, Level 2 [Member]
Non-Financial Assets and Liabilities:
Real estate	0	0
Fair Value, Inputs, Level 3 [Member]
Non-Financial Assets and Liabilities:
Real estate	$ 0	$ 24,161

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a nonrecurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

No definition available.

Name:	us-gaap_AssetsFairValueDisclosureNonrecurring
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant