XML 20 R42.htm IDEA: XBRL DOCUMENT v3.3.0.814

Junior Subordinated Debt/Trust Preferred Securities (Details)		1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2009 USD ($)	Aug. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) quarter	Sep. 30, 2014 USD ($)	Dec. 31, 2014
Debt Instrument [Line Items]
Gain on redemption of Jr subordinated debentures			$ 78,000	$ 0	$ 78,000	$ 0
Gain (loss) on fair value option of financial liability			148,000	95,000	346,000	(34,000)
Adjustment related to fair value calculations net of tax			86,000	$ 56,000	204,000	$ 20,000
Junior Subordinated Debt
Debt Instrument [Line Items]
Debt instrument, frequency of periodic payment	quarterly
Amount of junior subordinated debentures relating to trust preferred securities	$ 15,000,000		12,000,000.0		$ 12,000,000.0
Maximum number of consecutive quarters the entity defer interest payments without default or penalty | quarter					20
Debt instrument, unamortized discount		40.00%
Debt instrument, repurchased face amount		$ 3,000,000
Gain on redemption of Jr subordinated debentures					$ 78,000
Life of debt instrument					30 years
Fair value measurement option, gain (loss) on long-term debt instruments			$ 4,632,000		$ 4,632,000
Junior Subordinated Debt | Significant Unobservable Inputs Level 3 | Discounted Cash Flow Valuation Technique
Debt Instrument [Line Items]
Discount rate used in the valuation of debt instrument (in hundredths)					6.90%		6.87%
Junior Subordinated Debt | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate					129.00%
Junior Subordinated Debt | United Security Bank
Debt Instrument [Line Items]
Amount of junior subordinated debentures relating to trust preferred securities		$ 3,000,000.0

X

- Definition

Adjustment to the amount at which a liability incurred or settled in a current transaction between willing parties, that is, other than in a forced or liquidation sale, net of tax.

+ References

No definition available.

+ Details

Name:	ubfo_AdjustmentRelatedToFairValueCalculationsNetOfTax
Namespace Prefix:	ubfo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Debt Instrument, Amount Sold at Discount, Percentage

+ References

No definition available.

+ Details

Name:	ubfo_DebtInstrumentAmountSoldatDiscountPercentage
Namespace Prefix:	ubfo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The net gain (loss) resulting from the change in the fair value estimate of liabilities elected to be measured under the adoption of FAS 159.

+ References

No definition available.

+ Details

Name:	ubfo_GainLossonFairValueOptionofFinancialLiability
Namespace Prefix:	ubfo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Period over which long term debt is payable.

+ References

No definition available.

+ Details

Name:	ubfo_LongTermDebtInstrumentPeriod
Namespace Prefix:	ubfo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The terms of the debentures and trust indentures allow for the entity to defer interest payments for a number of maximum consecutive quarters without default or penalty.

+ References

No definition available.

+ Details

Name:	ubfo_MaximumNumberOfConsecutiveQuartersEntityDeferInterestPaymentsWithoutDefaultOrPenalty
Namespace Prefix:	ubfo_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 835



-SubTopic 30



-Section 55



-Paragraph 8



-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400



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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 835



-SubTopic 30



-Section 45



-Paragraph 2



-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

+ References

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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 942



-SubTopic 470



-Section 50



-Paragraph 3



-Subparagraph (c)



-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823



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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 210



-SubTopic 10



-Section S99



-Paragraph 1



-Subparagraph (SX 210.5-02.22)



-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

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

X

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

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

X

- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 820



-SubTopic 10



-Section 50



-Paragraph 2



-Subparagraph (bbb)



-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueInputsDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of long-term debt instruments that have contractual principal amounts and for which the fair value option has been elected.

+ References

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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 825



-SubTopic 10



-Section 50



-Paragraph 28



-Subparagraph (d)(2)



-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612

+ Details

Name:	us-gaap_FairValueOptionAggregateDifferencesLongTermDebtInstruments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 470



-SubTopic 50



-Section 40



-Paragraph 2



-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629



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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 230



-SubTopic 10



-Section 45



-Paragraph 28



-Subparagraph (b)



-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585



Reference 3: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 470



-SubTopic 50



-Section 40



-Paragraph 4



-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629

+ Details

Name:	us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_JuniorSubordinatedDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ValuationTechniqueAxis=ubfo_DiscountedCashFlowValuationTechniqueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=ubfo_UnitedSecurityBankMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: