Discontinued Operations - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended
Dec. 31, 2012
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Real Estate and Real Estate Joint Ventures	$ 93.8

The cash inflow from the sale of real estate held-for-investment and real estate joint ventures.

No definition available.

Name:	us-gaap_ProceedsFromRealEstateAndRealEstateJointVentures
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration