This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

Financial Instruments - Quantitative Information About Level 3 Fair Value Measurements (Detail) (USD $) In Thousands, unless otherwise specified			3 Months Ended
	Sep. 30, 2012 CDS Contract [Member]	Dec. 31, 2011 CDS Contract [Member]	Sep. 30, 2012 Swap Rate [Member]	Sep. 30, 2012 Discount Rate [Member]	Sep. 30, 2012 Credit Spread [Member]	Sep. 30, 2012 Constant Prepayment Rate [Member]	Sep. 30, 2012 Constant Prepayment Rate [Member] Minimum [Member]	Sep. 30, 2012 Constant Prepayment Rate [Member] Maximum [Member]	Sep. 30, 2012 Constant Default Rate [Member]	Sep. 30, 2012 Constant Default Rate [Member] Minimum [Member]	Sep. 30, 2012 Constant Default Rate [Member] Maximum [Member]	Sep. 30, 2012 Loss Severity [Member]	Sep. 30, 2012 Loss Severity [Member] Minimum [Member]	Sep. 30, 2012 Loss Severity [Member] Maximum [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value at September 30, 2012	$ 1,745	$ 1,339
Range							1.00%	25.00%		(0.40%)	100.00%		10.00%	80.30%
Weighted Average			2.39%	0.49%	1.09%	4.83%			4.80%			48.41%