Annual report pursuant to Section 13 and 15(d)

EMPLOYEE BENEFITS AND SHARE BASED COMPENSATION (Narrative) (Details)

v2.4.1.9
EMPLOYEE BENEFITS AND SHARE BASED COMPENSATION (Narrative) (Details) (USD $)
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Jan. 01, 2014
Defined Benefit Plan Disclosure [Line Items]        
Deferred compensation plans obligation to Board of Directors $ 10,300,000us-gaap_OtherDeferredCompensationArrangementsLiabilityCurrentAndNoncurrent $ 7,300,000us-gaap_OtherDeferredCompensationArrangementsLiabilityCurrentAndNoncurrent    
Salaries and benefit expense for incentive compensation 898,000ubsh_NonStockIncentiveCompensationForKeyManagement 939,000ubsh_NonStockIncentiveCompensationForKeyManagement 835,000ubsh_NonStockIncentiveCompensationForKeyManagement  
Number of stock option awards exercised 75,282us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised 50,119us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised 2,376us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised  
Intrinsic value of stock options exercised 573,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue 268,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue 7,400us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue  
Shares expected to be issued upon the exercise of stock 30,000ubsh_ShareBasedPaymentAwardOptionsSharesExpectedToBeIssuedCurrentYear      
Fair value of stock options exercised 1,800,000ubsh_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisedInPeriodFairValue 1,200,000ubsh_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisedInPeriodFairValue 36,000ubsh_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisedInPeriodFairValue  
Cash received from the exercise of stock options 1,200,000us-gaap_ProceedsFromStockOptionsExercised 927,000us-gaap_ProceedsFromStockOptionsExercised 31,000us-gaap_ProceedsFromStockOptionsExercised  
Tax benefit from exercise of equity-based awards 187,000us-gaap_DeferredTaxExpenseFromStockOptionsExercised 54,000us-gaap_DeferredTaxExpenseFromStockOptionsExercised 2,600us-gaap_DeferredTaxExpenseFromStockOptionsExercised  
Fair value of stock options vested 313,000us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1 335,000us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1 279,000us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1  
Restricted stock vesting percentage 50.00%ubsh_RestrictedStockVestingPercentage      
Intrinsic value of stock options outstanding 3,100,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue 3,500,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue 623,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue  
Unamortized compensation costs 3,402,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized      
Minimum [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Hours of service required for eligibility under plan 1000 hours      
1% through 3% [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Percentage of employer's match for 401(k) plan 100.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
/ us-gaap_StatementScenarioAxis
= ubsh_OneThroughThreePercentageMember 		     
1% through 3% [Member] | Minimum [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Percentage of employee's gross pay for 401(k) plan 1.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_StatementScenarioAxis
= ubsh_OneThroughThreePercentageMember 		     
1% through 3% [Member] | Maximum [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Percentage of employee's gross pay for 401(k) plan 3.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_StatementScenarioAxis
= ubsh_OneThroughThreePercentageMember 		     
4% through 5% [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Percentage of employer's match for 401(k) plan 50.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
/ us-gaap_StatementScenarioAxis
= ubsh_FourThroughFivePercentageMember 		     
4% through 5% [Member] | Minimum [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Percentage of employee's gross pay for 401(k) plan 4.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_StatementScenarioAxis
= ubsh_FourThroughFivePercentageMember 		     
4% through 5% [Member] | Maximum [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Percentage of employee's gross pay for 401(k) plan 5.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_StatementScenarioAxis
= ubsh_FourThroughFivePercentageMember 		     
401(K) Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Vesting period 5 years      
ESOP Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Vesting period 6 years      
2011 Plan [Member] | Minimum [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Vesting period 3 years      
2011 Plan [Member] | Maximum [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Vesting period 5 years      
Stock options term from the grant date 10 years      
StellarOne Bank [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Number of shares equivalent to each share of acquired entity       0.9739ubsh_BusinessAcquisitionNumberOfSharesEquivalentToEachShareOfAcquiredEntity
/ us-gaap_BusinessAcquisitionAxis
= ubsh_StellaroneBankMember
401 (K) plan, assets   $ 39,400,000us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsCurrentAndNoncurrent
/ us-gaap_BusinessAcquisitionAxis
= ubsh_StellaroneBankMember