Quarterly report pursuant to Section 13 or 15(d)

LOANS AND ALLOWANCE FOR LOAN LOSSES (Narrative) (Details)

v2.4.1.9
LOANS AND ALLOWANCE FOR LOAN LOSSES (Narrative) (Details) (USD $)
 3 Months Ended 12 Months Ended
Mar. 31, 2015
Dec. 31, 2014
Mar. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Loans $ 5,387,755,000us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome $ 5,345,996,000us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome $ 5,274,198,000us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
Loans and interest accruing 90 days past due 7,932,000us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing 10,047,000us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing  
Average investment in impaired loans 119,316,000us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment 141,184,000us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment  
Interest income recorded on impaired loans 1,221,000us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod 5,871,000us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod  
Nonaccrual loans 17,385,000us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus 19,255,000us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus  
Period for restructured loan to be considered default 90 days    
Recorded Investment 114,756,000us-gaap_ImpairedFinancingReceivableRecordedInvestment 132,180,000us-gaap_ImpairedFinancingReceivableRecordedInvestment  
Loans considered to be trouble debt restructurings 24,076,000us-gaap_FinancingReceivableModificationsRecordedInvestment 26,777,000us-gaap_FinancingReceivableModificationsRecordedInvestment  
Purchased Impaired (net of credit mark) 91,346,000us-gaap_FinancingReceivableAcquiredWithDeterioratedCreditQuality 105,788,000us-gaap_FinancingReceivableAcquiredWithDeterioratedCreditQuality 138,431,000us-gaap_FinancingReceivableAcquiredWithDeterioratedCreditQuality
purchased impaired loans (gross) 111,600,000ubsh_FinancingReceivableAcquiredWithDeterioratedCreditQualityGrossOutstandingBalance 126,300,000ubsh_FinancingReceivableAcquiredWithDeterioratedCreditQualityGrossOutstandingBalance  
Acquired Performing Loan Portfolio [Member]      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Loans 1,700,000,000us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
/ us-gaap_FinancialInstrumentAxis
= ubsh_AcquiredPerformingLoanPortfolioMember 		1,800,000,000us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
/ us-gaap_FinancialInstrumentAxis
= ubsh_AcquiredPerformingLoanPortfolioMember 		 
Remaining discount on acquired loans $ 23,800,000ubsh_RemainingDiscountOnAcquiredLoans
/ us-gaap_FinancialInstrumentAxis
= ubsh_AcquiredPerformingLoanPortfolioMember 		$ 24,300,000ubsh_RemainingDiscountOnAcquiredLoans
/ us-gaap_FinancialInstrumentAxis
= ubsh_AcquiredPerformingLoanPortfolioMember