| 
           LOANS AND ALLOWANCE FOR LOAN LOSSES (Loans Stated at Face Amount, Net of Unearned Income) (Details) (USD $) In Thousands, unless otherwise specified 
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           Mar. 31, 2015 
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           Dec. 31, 2014 
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           Mar. 31, 2014 
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        | Loans stated at face amount, net of unearned income | 
         
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        | Loans held for investment, net of deferred fees and costs | 
        
$ 5,387,755us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
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$ 5,345,996us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
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$ 5,274,198us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
 | 
      
      
        | Commercial Construction [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
 | 
         
 | 
         
 | 
      
      
        | Loans held for investment, net of deferred fees and costs | 
        
358,436us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_CommercialConstructionMember
 | 
        
341,280us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_CommercialConstructionMember
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        | Commercial Real Estate - Owner Occupied [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
 | 
         
 | 
         
 | 
      
      
        | Loans held for investment, net of deferred fees and costs | 
        
898,222us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_CommercialRealEstateOwnerOccupiedMember
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875,443us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_CommercialRealEstateOwnerOccupiedMember
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        | Commercial Real Estate - Non-Owner Occupied [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
 | 
         
 | 
         
 | 
      
      
        | Loans held for investment, net of deferred fees and costs | 
        
1,518,590us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_CommercialRealEstateNonOwnerOccupiedMember
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1,509,159us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_CommercialRealEstateNonOwnerOccupiedMember
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        | Raw Land and Lots [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
 | 
         
 | 
         
 | 
      
      
        | Loans held for investment, net of deferred fees and costs | 
        
197,759us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_RawLandAndLotsMember
 | 
        
211,225us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_RawLandAndLotsMember
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        | Single Family Investment Real Estate [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
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        | Loans held for investment, net of deferred fees and costs | 
        
416,984us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_SingleFamilyInvestmentRealEstateMember
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412,494us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_SingleFamilyInvestmentRealEstateMember
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        | Commercial and Industrial [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
 | 
         
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 | 
      
      
        | Loans held for investment, net of deferred fees and costs | 
        
426,490us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_CommercialAndIndustrialMember
 | 
        
393,776us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_CommercialAndIndustrialMember
 | 
         
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        | Other Commercial [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
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 | 
      
      
        | Loans held for investment, net of deferred fees and costs | 
        
80,416us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_OtherCommercialMember
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81,106us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_OtherCommercialMember
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        | Mortgage [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
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 | 
      
      
        | Loans held for investment, net of deferred fees and costs | 
        
466,804us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_MortgagesMember
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478,151us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_MortgagesMember
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        | Consumer Construction [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
 | 
         
 | 
         
 | 
      
      
        | Loans held for investment, net of deferred fees and costs | 
        
65,898us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_ConsumerConstructionMember
 | 
        
74,168us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_ConsumerConstructionMember
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        | Indirect Auto [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
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        | Loans held for investment, net of deferred fees and costs | 
        
203,369us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoansAutoFinancingReceivableMember
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199,411us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoansAutoFinancingReceivableMember
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        | Indirect Marine [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
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 | 
      
      
        | Loans held for investment, net of deferred fees and costs | 
        
43,643us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_IndirectMarineMember
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43,190us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_IndirectMarineMember
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        | HELOCs [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
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        | Loans held for investment, net of deferred fees and costs | 
        
491,116us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_HelocsMember
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500,579us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ubsh_HelocsMember
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        | Credit Card [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
 | 
         
 | 
         
 | 
      
      
        | Loans held for investment, net of deferred fees and costs | 
        
24,691us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerCreditCardFinancingReceivableMember
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24,225us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerCreditCardFinancingReceivableMember
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        | Other Consumer [Member] | 
         
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        | Loans stated at face amount, net of unearned income | 
         
 | 
         
 | 
         
 | 
      
      
        | Loans held for investment, net of deferred fees and costs | 
        
$ 195,337us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerOtherFinancingReceivableMember
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$ 201,789us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerOtherFinancingReceivableMember
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