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Stock Option Grants - Additional Information (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended 0 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Feb. 23, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock Options Granted, Number of Shares 83,400us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross    
Stock Options Outstanding, Number of Shares 83,400us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber  
Fair value risk-free interest rate 2.80%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate    
Treasury note rate term 10 years    
Fair value expected term 7 years 6 months    
Fair value dividend rate 1.50%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate    
Stock price volatility period 3 years    
Stock options aggregate intrinsic value $ 0.1us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue    
Omnibus Incentive Plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock option awards granted vesting period 1 year    
Stock option awards granted fully vested or to be vested contractual term 10 years    
Stock-based compensation expense related to stock option $ 0.3us-gaap_AllocatedShareBasedCompensationExpense
/ us-gaap_AwardTypeAxis
= usbi_OmnibusIncentivePlanMember
   
Stock Options Granted, Number of Shares   0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_AwardTypeAxis
= usbi_OmnibusIncentivePlanMember
 
Stock Options Outstanding, Number of Shares   0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= usbi_OmnibusIncentivePlanMember
 
Non Qualified Stock Options [Member] | Subsequent Event [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock Options Granted, Number of Shares     96,150us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
/ us-gaap_AwardTypeAxis
= usbi_NonQualifiedStockOptionsMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember