Annual report pursuant to Section 13 and 15(d)

ACQUISITIONS (Outstanding Principal Balance and Carrying Amount of Acquired Impaired Loans) (Details)

v2.4.1.9
ACQUISITIONS (Outstanding Principal Balance and Carrying Amount of Acquired Impaired Loans) (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Jan. 01, 2014
Business Acquisition [Line Items]        
Total $ 105,788us-gaap_FinancingReceivableAcquiredWithDeterioratedCreditQuality $ 3,622us-gaap_FinancingReceivableAcquiredWithDeterioratedCreditQuality $ 4,565us-gaap_FinancingReceivableAcquiredWithDeterioratedCreditQuality  
StellarOne Bank [Member]        
Business Acquisition [Line Items]        
Contractually required principal and interest payments       214,803us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAcquiredDuringPeriodContractuallyRequiredPaymentsReceivableAtAcquisition
/ us-gaap_BusinessAcquisitionAxis
= ubsh_StellaroneBankMember
Nonaccretable difference       (34,696)us-gaap_CertainLoansAcquiredInTransferNonaccretableDifference
/ us-gaap_BusinessAcquisitionAxis
= ubsh_StellaroneBankMember
Cash flows expected to be collected       180,107us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAcquiredDuringPeriodCashFlowsExpectedToBeCollectedAtAcquisition
/ us-gaap_BusinessAcquisitionAxis
= ubsh_StellaroneBankMember
Accretable difference       (34,653)us-gaap_CertainLoansAcquiredInTransferAccretableYield
/ us-gaap_BusinessAcquisitionAxis
= ubsh_StellaroneBankMember
Total       $ 145,454us-gaap_FinancingReceivableAcquiredWithDeterioratedCreditQuality
/ us-gaap_BusinessAcquisitionAxis
= ubsh_StellaroneBankMember