| 
           LOANS AND ALLOWANCE FOR LOAN LOSSES (Schedule of TDR by Class and Modification Type) (Details) (USD $) 
        In Thousands, unless otherwise specified  | 
        3 Months Ended | |
|---|---|---|
| 
           Mar. 31, 2015
 
          loan 
         | 
        
           Mar. 31, 2014
 
          loan 
         | 
      |
| Financing Receivable, Modifications [Line Items] | ||
| No. of Loans | 1ubsh_FinancingReceivableNewModificationsNumberOfContracts | 4ubsh_FinancingReceivableNewModificationsNumberOfContracts | 
| Recorded investment at period end | $ 19ubsh_FinancingReceivableNewModificationsRecordedInvestment | $ 3,141ubsh_FinancingReceivableNewModificationsRecordedInvestment | 
| Troubled Debt Restructuring Term Modification at Market Rate [Member] | ||
| Financing Receivable, Modifications [Line Items] | ||
| No. of Loans | 
1ubsh_FinancingReceivableNewModificationsNumberOfContracts / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = ubsh_TroubleDebtRestructuringTermModificationAtMarketRateMember  | 
        
4ubsh_FinancingReceivableNewModificationsNumberOfContracts / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = ubsh_TroubleDebtRestructuringTermModificationAtMarketRateMember  | 
      
| Recorded investment at period end | 
19ubsh_FinancingReceivableNewModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = ubsh_TroubleDebtRestructuringTermModificationAtMarketRateMember  | 
        
3,141ubsh_FinancingReceivableNewModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = ubsh_TroubleDebtRestructuringTermModificationAtMarketRateMember  | 
      
| Troubled Debt Restructuring Term Modification at Market Rate [Member] | Commercial Real Estate - Owner Occupied [Member] | ||
| Financing Receivable, Modifications [Line Items] | ||
| No. of Loans | 
1ubsh_FinancingReceivableNewModificationsNumberOfContracts / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_CommercialRealEstateOwnerOccupiedMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = ubsh_TroubleDebtRestructuringTermModificationAtMarketRateMember  | 
      |
| Recorded investment at period end | 
2,732ubsh_FinancingReceivableNewModificationsRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_CommercialRealEstateOwnerOccupiedMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = ubsh_TroubleDebtRestructuringTermModificationAtMarketRateMember  | 
      |
| Troubled Debt Restructuring Term Modification at Market Rate [Member] | Single Family Investment Real Estate [Member] | ||
| Financing Receivable, Modifications [Line Items] | ||
| No. of Loans | 
1ubsh_FinancingReceivableNewModificationsNumberOfContracts / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_SingleFamilyInvestmentRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = ubsh_TroubleDebtRestructuringTermModificationAtMarketRateMember  | 
      |
| Recorded investment at period end | 
113ubsh_FinancingReceivableNewModificationsRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_SingleFamilyInvestmentRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = ubsh_TroubleDebtRestructuringTermModificationAtMarketRateMember  | 
      |
| Troubled Debt Restructuring Term Modification at Market Rate [Member] | Commercial and Industrial [Member] | ||
| Financing Receivable, Modifications [Line Items] | ||
| No. of Loans | 
1ubsh_FinancingReceivableNewModificationsNumberOfContracts / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_CommercialAndIndustrialMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = ubsh_TroubleDebtRestructuringTermModificationAtMarketRateMember  | 
        |
| Recorded investment at period end | 
19ubsh_FinancingReceivableNewModificationsRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_CommercialAndIndustrialMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = ubsh_TroubleDebtRestructuringTermModificationAtMarketRateMember  | 
        |
| Troubled Debt Restructuring Term Modification at Market Rate [Member] | Other Commercial [Member] | ||
| Financing Receivable, Modifications [Line Items] | ||
| No. of Loans | 
2ubsh_FinancingReceivableNewModificationsNumberOfContracts / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_OtherCommercialMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = ubsh_TroubleDebtRestructuringTermModificationAtMarketRateMember  | 
      |
| Recorded investment at period end | 
$ 296ubsh_FinancingReceivableNewModificationsRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_OtherCommercialMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = ubsh_TroubleDebtRestructuringTermModificationAtMarketRateMember  | 
      |
| X | ||||||||||
| 
             
- Definition 
          Financing receivable new modifications number of contracts. No definition available. 
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| X | ||||||||||
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- Definition 
          Financing Receivable New Modifications Recorded Investment No definition available. 
  | 
        
| X | ||||||||||
| 
             
- Details 
          
  | 
        
| X | ||||||||||
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- Details 
          
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