Notes Receivable - Loans Receivable on Real Estate (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2014	Mar. 31, 2013
Mortgage Loans On Real Estate [Abstract]
Balance at January 1	$ 72,218	$ 60,378
Additions:
Interest	473	123
Accretion of discount	227	214
Deductions:
Payments of principal and interest	(113)	(11,310)
Balance at March 31	$ 72,805	$ 49,405

Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of passage of time.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 932

-SubTopic 235

-Section 50

-Paragraph 35

-Subparagraph (h)

-URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62500-109447

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