Loan Receivables - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Loans Receivable [Line Items]
Reserve for uncollectible loan receivables, balance	$ 3.2	$ 0
Gross balance of loan receivables for which a reserve on a loan-by-loan basis for uncollectible loan receivables has been applied	$ 3.2	$ 0

Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (a)(4)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5212-111524

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