Name:	ubsi_AmortizedCostOfAvailableForSaleSingleIssueTrustPreferredSecurities
Namespace Prefix:	ubsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The number of available for sale securities in the investment portfolio.

No definition available.

Name:	ubsi_AvailableForSaleSecuritiesNumber
Namespace Prefix:	ubsi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Represents the minimum amount of market capitalization for banks with obligations in the single-issue trust preferred portfolio.

No definition available.

Name:	ubsi_CapitalizationOfBanksEqualToOrGreaterThanInSingleIssueTrustPreferredPortfolio
Namespace Prefix:	ubsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of investment in equity securities at estimated fair value.

No definition available.

Name:	ubsi_EquitySecurities
Namespace Prefix:	ubsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The carrying amount of investments securities that serve as collateral for borrowings.

No definition available.

Name:	ubsi_InvestmentSecuritiesPledgedAsCollateral
Namespace Prefix:	ubsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

The percentage of the portfolio of corporate debt securities issued by domestic or foreign corporate business, banks and other entities with a promise of repayment.

No definition available.

Name:	ubsi_PercentOfCorporateSecuritiesPortfolio
Namespace Prefix:	ubsi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percent of municipal bond portfolio supported by the general obligation of the issuing municipality which allows for the securities to be repaid by any means available to the municipality.

No definition available.

Name:	ubsi_PercentOfMunicipalBondPortfolioWithCreditSupport
Namespace Prefix:	ubsi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents percentage of guarantee repayment by government.

No definition available.

Name:	ubsi_PercentageOfGuaranteeRepaymentByGovernment
Namespace Prefix:	ubsi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

No definition available.

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

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

No definition available.

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

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27290-111563

Name:	us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Amount of other-than-temporary impairment (OTTI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), recognized in earnings.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 8A
-URI http://asc.fasb.org/extlink&oid=118954083&loc=SL6284422-111562

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

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.

No definition available.

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

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_InternalInvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_InternalNoninvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_InternalCreditAssessmentAxis=ubsi_SplitRatedBondsInvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_InternalCreditAssessmentAxis=ubsi_UnratedBondsInvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

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

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

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

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

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

Name:	invest_InvestmentAxis=ubsi_TrupcdosMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: