Name:	ubsi_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansActuarialGainLossArisingDuringPeriodNetTax
Namespace Prefix:	ubsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Other comprehensive income loss reclassification adjustment before tax.

No definition available.

Name:	ubsi_OtherComprehensiveIncomeLossReclassificationAdjustmentBeforeTax
Namespace Prefix:	ubsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Other comprehensive income reclassification adjustment net of tax.

No definition available.

Name:	ubsi_OtherComprehensiveIncomeReclassificationAdjustmentNetOfTax
Namespace Prefix:	ubsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Other comprehensive income reclassification adjustments for gains included in income.

No definition available.

Name:	ubsi_OtherComprehensiveIncomeReclassificationAdjustmentsForGainsIncludedInIncome
Namespace Prefix:	ubsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Other comprehensive income reclassification of unrealized gain to income statement tax expense benefit.

No definition available.

Name:	ubsi_OtherComprehensiveIncomeReclassificationOfUnrealizedGainToIncomeStatementTaxExpenseBenefit
Namespace Prefix:	ubsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The amount of the transition obligation or asset recognized in net periodic benefit cost.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (h)(6)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

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

- Details

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

- Details

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

Amount after tax, before reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement benefit plans.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 10A

-Subparagraph (i-k)

-URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669646-108580

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

Amount before tax, after reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.

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

Amount after tax and reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.

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

Amount of tax (expense) benefit related to cost (credit) of benefit changes attributable to plan participants' prior service resulting from a plan amendment or plan initiation that has not been recognized in net periodic benefit cost (credit).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e640-108580

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

Amount before tax of reclassification adjustment from accumulated other comprehensive income for unrealized loss realized upon the write-down of available-for-sale securities.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e637-108580

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 15

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e689-108580