XML 92 R81.htm IDEA: XBRL DOCUMENT v3.21.2

INVESTMENT SECURITIES - Significant Assumptions in Valuation of Private Label MBS (Detail) - MBS [Member] - Private label [Member]	Sep. 30, 2021	Dec. 31, 2020
Discount rate [Member] | Weighted Average [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.127	0.122
Discount rate [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.127	0.122
Discount rate [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.127	0.122
Prepayment rate [Member] | Weighted Average [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.158	0.121
Prepayment rate [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.048	0.012
Prepayment rate [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.241	0.188
Projected Cumulative Loss Rate [Member] | Weighted Average [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.096	0.102
Projected Cumulative Loss Rate [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.002	0.026
Projected Cumulative Loss Rate [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.186	0.223

X

- Definition

Value of input used to measure investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleMeasurementInput
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputDiscountRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_WeightedAverageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputPrepaymentRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputLossSeverityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: